Abstract: Megasporogenesis,microsporogenesis and the development of female gametophyte and male gametophyte of Puccinellia tenuiflora using normal paraffin method are studied in this paper. The main results are as follows: (1) The microspore mother cell undergoes meiosis before it turns into microspore tetrad. Its cytokinesis is successive type, and its tetrad is bilateral. (2) The mature pollen grains are three-celled, and each has a single germinal aperture. (3) The anther wall is composed of four layers, epidermis, endothecium, middle layer and tapetum respectively, and the tapetum is secretory type. The development of anther wall follows the monocotyledonous type. (4) Simple ovary, uniovulate, anatropous ovule and tenuinucellate nucellus. The megasporocyte divides into linear megaspore tetrad after meiosis. The chalazal end megaspore is functional. (5) The embryo sac is the Polygonum type. When the embryo sac is mature, the antipodal cells divide into four to six cells. There may be DNA duplication processes for many times within them.