Abstract: 【Objective】 Learn the morphology and microstructure of flowers, pistils and stamens in Styrax tonkinensis, and probe into the reasons of pollen abortion.【Method】The macrostructure, microstructure and ultrastructure of the pistils and stamens were studied by light and electron microscopy. 【Result】① There were 10 stamens composed of filaments and anthers in each bisexual flower. The width and length of a filament was approximately(0.38±0.12)mm and(8.24±0.72)mm, respectively. The mature anthers were composed of two narrow circular chambers. Three or four germinal furrows in the exine of mature pollen with finely reticulate ornamentation were observed by scanning electron microscopy(SEM). Furthermore, we observed a form of shrunken, poorly developed pollen. Using transmission electron microscopy, we observed that in well-developed pollen cells, there were two layers in the pollen wall, a dense cytoplasm, some Golgi apparatus, a large number of mitochondria, and a high proportion of electron dense materials and starch grains. ② There was one pistil per flower composed of a stigma, style and ovary. There were “Y”-type furrow and ellipsoidal mastoids on the stigma, and secretions after pollination. The style was hollow, and there were many anatropous ovules attached to the placenta on the inner wall of its three-chambered ovary. In the late period of development, only one or two of these ovules developed into seeds, whereas the others became degraded. 【Conclusion】The characteristics of S. tonkinensis flower were accordance with Styracaceae. The pollen had 3 forms. The stigma was wet type. The ovule was anatropous. There were rich cytoplasm and more organelles in the cells of the pollen and the integument.