[Objective] The correlation between genetic distance and heterosis of the major Brassica napus L. cultivars in Yunnan Province was analyzed. [Method] The genetic distances among the 8 major Brassica napus L. cultivars in Yunnan Province were investigated with the SSR molecular marker technique. Moreover, the correlation between genetic distance and field appearance of heterosis was ana-lyzed. [Result] There was a certain correlation between the genetic distance and heterosis of crossing parents (P〉0.05). [Conclusion] It is difficult to predict the het-erosis of Brassica napus L. cultivars and to screen parents by using the SSR molecular marker technique.