Abstract:In order to broaden the gene bank and to screen germplasm resources for cross breeding, 134 foreign cotton germplasms were used as experimental materials. The study involved the variation of the main fibre quality and agronomic traits, the genetic diversity index and the correlation of main quality traits. Taking the main agronomic and fiber quality charactersas the index, the clustering and principal components analysis were used for these samples.The results showed that, as far as fiber quality was concerned, genetic diversity index of fiber regularity degree(5.16)was highest,variation coefficient of mcronaire value(11.96%)was highest; In terms of agronomic traits, genetic diversity index of lint percentage before the frost(5.42)was highest, variation coefficient of sterile seed ratio(49.18%)was highest, and these cotton germplasms were abundant in genetic diversity; The regularity degree was significantly positive correlated with the average length of upper half and breaking tenacity, breaking tenacity was significantly positive correlated with average length of upper half; The principal components analysis of 10 agronomic and 5 quality traits showed that the accumulation indices of top 6 principal components was up to 75.277%; Cluster analysis showed that 134 cotton germplasms were classified into 5 groups when the main quality traits are taken as the index, the groupⅡ had the best fiber quality; According to main agronomic characters, these germplasms were classified into 3 groups, the groupⅠhad maximum yield;14 germplasms such as Mei1870、Mei1884 and FM1830 etc , in which both the quality and yield traits are excellent for cross breeding have been screened by means of comprehensive analysis about 35 germplasms of quality traitsⅡgroup and 58 germplasms of agronomic traitsⅠgroup.