Abstract: The effect of calcium on the absorption of boron by the rapeseedlings, and mobility of boron in plants were studied in this paper. Boron enhanced the absorption of N, P, K, Ca. Boron uptakeand accumulation in young leaves were reduced, while in oldleaves were increased when the calcium concentration of the medium was increased. There translocation index ( ratio of bown concentration in young leaves: old leaves ) of boron was greater inmedium containing 0.025 ppm B than in 0.5 ppm B, and it decreascd when there calcium was increased. These results showed that B isremobilized under boron deficiency, and boron translocation fromold leaves to young leaves appeared to be inhibited by high concentraction of calcium.