Abstract:The effect of boron deficiency (0. 02 ppm of hot water soluble boron soil)on the development of floral organs of NY-8 (Brassica nalrus L. )was obvious. Some abnormal features were observed: pollen sac shrinkage, abnormal development of tapetum, abortion occurred from the stage of PMC to the unicellular pollen ,stigma exposed,poor development of papillae, arrested differentiation of some ovules and embryo sacs etc. The results suggest that the abortion of stamen and pistil in rape may be one of the reasons for yield decrease