Abstract: Pot culture was conducted to study the effect of boron and molybdenum on seed yield and oil quality of two rapeseed (Brassica napus)cultivars[double low(low erucic acid content, low glucosindate content)cultivar: Zhongshuang 6 and double high cultivar: Zhongyou 821]. The results showed that comparing with CK, the 3 treatments(+B、+Mo、+B+Mo) had significant effects on seed yields of Zhongshuang 6 and Zhongyou 821. The +Mo treatment had the best response on the yield of Zhongshuang 6, but for Zhongyou 821, +B or +B+Mo treatment had better response than (+Mo) treatment. Single supplying B or Mo, the production increase effect of Zhongshuang 6 was better than that of Zhongyou 821, while for +B+Mo treatment, the effect of the latter was better than that of the former. The oil content of two cultivars in the 3 treatments were significantly higher than CK, the rate of increase in oil production of Zhongshuang 6 and Zhongyou 821 was ranged 4.3%～5.1% and 5.7%～6.2%, respectively. There was no significant difference among 3 treatments. For Zhongshuang 6 and Zhongyou 821, the highest amount of increase in (production) was got in +Mo and +B treatment, respectively. Erucic acid content of the two cultivars in 3 treatments (decreased) compared with CK, for Zhongshuang 6, erucic acid content in +Mo and +B+Mo treatments decreased by 34.62% and 27.62%, respectively. For Zhongyou 821, the rate of decreased scope was between 3.2% and 13.8%. There were a significant decrease in glucosindate content for +B and +B+Mo treatments. Glucosindate content (decreased) compared with CK, the decreasing scope of Zhongshuang 6 was between 1.54% and 13.1%. There was a significant difference between +Mo and +B+Mo treatment, and the decreasing scope of Zhongyou 821 was between 9.0% and 29.1%.The results in this study showed that B or Mo nutrition had a positive correlation with seed yield and oil content, however, the effect on increasing seed yield and improving quality was different among various cultivars.