Objective  To study the genetic diversity of castor (Ricinus communis)germplasm resources, reveal the characteristic and distribution of excellent germplasm, and provide a theoretical basis for castor germplasm resources innovation and breed improvement.

Method  Fourty castor germplasm resources from China and abroad were used as material, and 20 traits were assessed by the clustering method and principal component analysis. The effects of castor quantitative characters on yield per plant were analayzed.

Result  The results of cluster analysis showed 40 germplasm resources belonged to five groups (Ⅰ-Ⅴ). Group Ⅰ was the parents of progenies with large raceme, group Ⅱ was the parents of progenies with large seed size and high yield potential, group Ⅲ was the parents of progenies with small seed size, more branch and capsule, group Ⅳ was the parents of progenies with high yield, and group Ⅴ was the parents of progenies with both large raceme and seed size. According to the results of principal component analysis, thirteen quantitative traits were classified to five major factors, namely bearing height of primary raceme, effective capsule number, capsule number of primary raceme, hundred-grain weight and effective raceme number of single plant. The cumulative contribution was about 87.06%, and the bearing height of primary raceme was the essential factor.

Conclusion  Fourty germplasm resources possess rich germplasm types and different traits, and might be used as excellent germplasm materials for breeding in future.