The development history of water quality index was discussed. Several mature and widely used water quality indexes in western countries, including their background and application fields, were introduced, aiming to offerring reference for surface water quality assessment in our country. Comprehensively evaluation of water quality index and its application showed that the Canadian Council of Ministers of the Environment water quality index(CCMEWQI)is a recommended water quality evaluation method. It is recommended that proper water quality index assessment method for headwater areas in China should be developed based on CCMEWQI.