In view of the needs for market sales analysis by transmission network service providers, a comprehensive index system is proposed which can be used to analyse the market trends and sales effectiveness. This index system is primarily based on analytical theme and supplemented by time sequential information for construction purpose. In view of analytical theme, it can be classified into four major parts, including market environment, management analysis, market forecasting and post-analysis. Based on time sequential information, it can be classified into already happened, yet to happen and post-evaluation. The index system considers current research and practice. It also includes some newly developed indices featuring in marketing, including market share, market concentration rate, key customer discerning and business process tracking, etc. It aims at giving a comprehensive, thorough assessment of the development status of power sale market. The index system has formed a solid basis for the power sale market analysis, forecasting report, and the corresponding software system of State Grid Company of China, providing a standardized, scientific and efficient tool for power marketing analysis, operations and management. This work is supported by Program for New Century Excellent Talents in University (No.NCET-07-0484) and the Fok Ying-Tong Education Foundation (No.104020).