In this study,genetic relationship and diversity based on SSR markers were investigated in 91 rapeseed accessions including registered varieties,backbone parents,and high-oil inbred lines,as well as 8 references from Brassica juncea,B.campestris and B.carinata.48 pairs of selected SSR primers from A and C genomes were employed and 255 polymorphic bands were detected.UPGMA clustering showed that 99 accessions were divided into 5 groups.The largest group,group Ⅰ included 89 B.napus materials.Group Ⅱ only included 2 white flower accessions named Ethiopia mustard and G8.Group Ⅲ consisted of 4 B.juncea landraces.Group Ⅳ were 3 B.campestris landraces and group Ⅴ contained only a mustard named Qinjie 2008,respectively.The 89 B.napus in group Ⅰ could be further divided into 5 subgroups.Subgroup 1 included 43 materials,most of which were restorer lines from Shaanxi and materials from Huazhong Agricultural University and Zhejiang.Subgroup 2 had 9 materials mainly from Shaanxi.12 materials were included in subgroup 3 and most of them were Guizhou and foreign materials.Subgroup 4 consisted of 19 materials mainly from Oil Crops Research Institute,CAAS,Zhejiang Academy of Agricultural Sciences,and Anhui.Subgroup 5 included 6 materials,such as Zheyou 758 and 147C.Most materials from same institutions had a higher similarity.The reason might be that these varieties or lines were bred with limited core inbred lines.The results could offer helpful information for rapeseed breeding and utilization of heterosis.