Abstract: For further study on leaf boron forms of rape (Brassica napus L.) with different boron efficient at flowering stage, two boron efficient (9589,9590), two boron inefficient rape cultivars (9141,95105) and their four F1 hybrid (951059589, 951059590, 91419589, 91419590) were used in this pot experiment. The results showed that the water soluble boron(S-B) content and bound boron(B-B) content in boron efficient cultivars was lower, while the semi bound boron(SB-B)content was higher, on the contrary, in the boron inefficient cultivars, and the results in F 1 hybrid were just between that in boron efficient cultivars and in boron inefficient cultivars. A balance of boron forms was established, which showed boron forms had a close relation with boron efficiency, and it may uncover the physiological mechanism of boron efficiency.