Abstract: From the ecological point of view, the relationship between satsuma orange fruit quality and ecological conditions of the citrus growing area in China was investigated. In order to improve the fruit quality of satsuma, the author suggests, (1) to choose those areas to growing citrus where the ecological condition is suitable for citrus; (2) to build shelter-belt for improving ecological conditions of the citrus plantation; (3)to improve the capital construction of the citrus plantations for increasing the capability of citrus trees against natural calamities; (4) to improve technology of culture and management and popularize the fine strains of the citrus.

Key words: Dominant natural enemy, Aphis gossypii population, Predation, Grey relational grade