Abstract: Since the middle of the 20th century, when the electron microscope was applied in this field, the study of the pollen has developed in depth and some breakthoughs have been made. In this article, the ultrastructure study of the pollen development will be introduced briefly in four respects as follows: 1) The morphological change and the biological significance of the callose wall deposit, cyto- plasm fusion and the cytoplasm recomposition, during the meiosis of the microsporocytes; 2) The distribution of cell organs, the division pattens of generative cells, and the introduction of terms of germ u-nit and sperm heterogeneity during the development of male gametophytes; 3) The distribution and functions of the pollen exine pattens, the internal structure and the pollen-wall proteins; 4) The morphological description of pollen abortion and the discussion of the mechanism. The agreement, as well as the disagreement, of the studies will be all introduced objectively.