Idesia polycarpa is an important fruit-oil tree, with high yield, high oil content of fruit and featuring enormous development potential. Most of the published studies mainly focused on seedling propagation, growth and development and oil processing, while there were few studies of I. polycarpar fruit phenotype traits with environment factors, which is important for high yield, so the study with the ccorrelation of I. polycarpar fruit phenotype traits and environment factors will provide scientific basis for its' high-quality development. To determine the variation of fruit phenotypic traits of I. polycarpa and their relationship with environmental factors, fourteen populations of I. polycarpa were systematically analyzed by means of variance analysis, correlation analysis, cluster analysis and principal component analysis. The results showed that:(1) there was great variation of the 9 fruit phenotypic traits within and among populations of I. polycarpa. The coefficient of variation (CV) of each phenotypic trait among populations was 6.47%-32.51%, while those within population was 4.69%-35.21%. The CV of single spike mass and fruit mass of single spike was larger, while that the single of fruit cross diameter, single fruit longitudinal and single fruit weight was all smaller. The average value of CV of the Forest Seedling Breeding Engineering Technology Center of Henan Agricultural University population was the largest and that of the Fangshan village, Sichuan Province population was the smallest. Ear phenotypic traits of I. polycarpa were significantly and positively correlated with fruit yield traits. Through the cluster analysis, the fourteen populations of I. polycarpa could be divided into four groups, among which group Ⅳ showed outstanding breeding advantages of large spike and single fruit weight. (2) Soil pH of I. polycarpa was 5.36-8.49, most of that were acidic. The contents of soil available nitrogen, phosphorus and potassium were low. (3) The total nitrogen among environmental factors had a greater influence on fruit phenotypic traits of I. polycarpa, and there were significant correlations between soil pH, content of available phosphorus and fruit phenotypic traits. There was abundant variation on fruit phenotypic traits of I. polycarpa. The ear shape had significant influence on its yield which could be used as an evaluation index for breeding of I. polycarpa. Soil pH and the content of available phosphorus can be the key factor influencing the fruit phenotypic traits of I. polycarpa. This suggests that increasing the yield of I. polycarpa may be achieved by changing soil pH and the content of available phosphorus.