A comparative developmental study of anther in two male sterile lines of purple caitai indicated that the anther of male sterile lines that do not contain pollen grains degenerated absolutely.Improved radish CMS lines were similar to male fertile line in anther development up to the tetrad stage;after this stage,the tapetal cells became larger and pressed microspore tightly thereby causing degeneration;but among ogura CMS line,53% of the anther development was inhibited before the stage of archesporial cell and had no differentiation of microsporangium,47% of the anther had differentiation of microsporangium which occupied small volume of the anther.The fate of microspore which aborted at uninucleate pollen stage is similar to improved radish CMS lines.