FORM 6-K SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 Report of Foreign Private Issuer Pursuant to Rule 13a-16 or 15d-16 of the Securities Exchange Act of 1934 For the month of June, 2004 (Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.) Form 20-F __X__ Form 40-F _____ (Indicate by check mark whether the registrant by furnishing the information contained in this form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.) Yes ____ No __X__ (If "Yes" is marked, indicate below the file number assigned to registrant in connection with Rule 12g3-2(b): 82-__________. ) N/A Huaneng Power International, Inc. West Wing, Building C, Tianyin Mansion No. 2C Fuxingmennan Street Xicheng District Beijing, 100031 PRC This Form 6-K consists of: An announcement of tariff adjustments, made on June 17, 2004, in English by Huaneng Power International Inc. The Stock Exchange of Hong Kong Limited takes no responsibility for the contents of this announcement, makes no representation as to its accuracy or completeness and expressly disclaims any liability whatsoever for any loss howsoever arising from or in reliance upon the whole or any part of the contents of this announcement. HUANENG POWER INTERNATIONAL, INC. (a Sino-foreign joint stock limited company incorporated in the People's Republic of China) (Stock Code: 902) ADJUSTMENTS OF TARIFFS This announcement is made pursuant to Rule 13.09(2) of the Rules Governing the Listing of Securities on the Stock Exchange of Hong Kong Limited. Huaneng Power International, Inc. (the "Company") announced the adjustments of tariffs of some of its power plants. According to documents issued by the National Development and Reform Commission, the on-grid tariffs (including VAT) of some of Company's power plants are to be adjusted as follows: ----------------------------------------------------------------------------------------------------------------------- Number of Utilisation Hours Tariff Adjustments Approved Tariff Corresponding to for Excessive Power Plant Adjustments Approved Tariff Generation Effective Date ----------------------------------------------------------------------------------------------------------------------- Fuzhou Power Plant Adjusted from Save for the agreed generation, all 15th June 2004 RMB372/MWh to generation to be charged in accordance RMB372.5/MWh with approved tariff. ----------------------------------------------------------------------------------------------------------------------- Shang'an Power Plant Adjusted from Adjusted from Adjusted from 15th June 2004 RMB341/MWh to RMB324/MWh 5,000 hours to RMB194/MWh to 5,500 hours RMB196/MWh ----------------------------------------------------------------------------------------------------------------------- Shidongkou First Adjusted from Adjusted from Adjusted from 15th June 2004 Power Plant RMB266.5/MWh to 4,800 hours to RMB224/MWh to RMB281/MWh 5,500 hours RMB260/MWh ----------------------------------------------------------------------------------------------------------------------- Shidongkou Second Adjusted from Adjusted from Adjusted from 15th June 2004 Power Plant RMB375.8/MWh to 4,900 hours to RMB224/MWh to RMB374/MWh 5,500 hours RMB260/MWh ----------------------------------------------------------------------------------------------------------------------- Dezhou Power Plant Generating units 1 to 4 5,500 hours Adjusted from 15th June 2004 adjusted from RMB200/MWh to RMB352.50/MWh to RMB260/MWh RMB354/MWh; Generating units 5 and 6 adjusted from RMB320/MWh to RMB321.50/MWh ----------------------------------------------------------------------------------------------------------------------- Jining Power Plant Generating units 1 to 4 5,500 hours Adjusted from 15th June 2004 adjusted from RMB200/MWh to RMB280.76/MWh to RMB260/MWh RMB282.26/MWh; Generating units 5 and 6 adjusted from RMB320/MWh to RMB321.50/MWh ----------------------------------------------------------------------------------------------------------------------- Weihai Power Plant Adjusted from 5,500 hours Adjusted from 15th June 2004 RMB395.5/MWh to RMB200/MWh to RMB397/MWh RMB260/MWh ----------------------------------------------------------------------------------------------------------------------- Xindian Power Plant Adjusted from RMB 5,500 hours Adjusted from 15th June 2004 320/MWh to RMB321.5/MWh RMB200/MWh to RMB260/MWh ----------------------------------------------------------------------------------------------------------------------- Shantou Coal-fired Adjusted from All generation to be charged in accordance 15th June 2004 Power Plant RMB443.41/MWh to with approved tariff. RMB449.41/MWh ----------------------------------------------------------------------------------------------------------------------- Nantong Power Plant Adjusted from Adjusted from Adjusted from 15th June 2004 RMB341/MWh to RMB338/MWh 4,864 hours to RMB240/MWh to 5,500 hours RMB280/MWh ----------------------------------------------------------------------------------------------------------------------- Nanjing Power Plant Adjusted from Adjusted from Adjusted from 15th June 2004 RMB341/MWh to RMB338/MWh 4,864 hours to RMB240/MWh to 5,500 hours RMB280/MWh ----------------------------------------------------------------------------------------------------------------------- Taicang Power Plant Adjusted from Adjusted from Adjusted from 15th June 2004 RMB372/MWh to 4,937 hours to RMB240/MWh to RMB365/MWh 5,500 hours RMB280/MWh ----------------------------------------------------------------------------------------------------------------------- Huaiyin Power Plant Adjusted from Adjusted from Adjusted from 15th June 2004 RMB350/MWh to RMB344/MWh 4,749 hours to RMB240/MWh to 5,500 hours RMB280/MWh ----------------------------------------------------------------------------------------------------------------------- Changxing Power Plant Adjusted from Adjusted from Adjusted from 15th June 2004 RMB339.16/MWh to 6,000 hours to RMB261/MWh to RMB371/MWh 5,500 hours RMB328/MWh ----------------------------------------------------------------------------------------------------------------------- Yushe Power Plant Generating units 1 and 5,500 hours Adjusted from 15th June 2004 2 remaining unchanged RMB164/MWh to (i.e. RMB308/MWh); RMB196/MWh Phase Two new generating units 3 and 4 to be fixed at RMB250/MWh ----------------------------------------------------------------------------------------------------------------------- The adjustments of tariffs will result in an increase of overall average settled tariff, and lead to certain increase of the annual income, of the Company. By Order of the Board Huang Long Company Secretary As at the date of this announcement, the directors of the Company are: Li Xiaopeng Gao Zongze (Non-executive director) (Independent director) Wang Xiaosong Zheng Jianchao (Non-executive director) (Independent director) Ye Daji Qian Zhongwei (Non-executive director) (Independent director) Huang Jinkai Xia Donglin (Non-executive director) (Independent director) Liu Jinlong (Non-executive director) Shan Qunying (Non-executive director) Yang Shengming (Non-executive director) Xu Zujian (Non-executive director) Beijing, the PRC 17th June, 2004 SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the under-signed, thereunto duly authorized. HUANENG POWER INTERNATIONAL, INC. By /s/ Wang Xiaosong ------------------------------ Name: Wang Xiaosong Title: Vice Chairman Date: June 17, 2004