Abstract: With 5 male sterile lines in Brassica napus L.as materials,the development of buds and stamens and pistils of male sterile lines in B.napus L.were researched and maked a comparison with the control group.The statistic result indicated that the dry weight of buds and stamens of male sterile lines in B.napus L.are much smaller than the control group while the pistils are much larger.And there existed a turning point in the growth curve of the stamens and pistils of male sterile lines at the same time,but in different directions.This implied that after the abortion of the stamens the soluble materials were partly carried to pistils,resulting in the extraordinary expansion of the pistils.