Paraffin sectioning and microscopic technique are used to reveal the mega-/micro-sporogenesis and female-/male-gametogenesis of Hosta plantagine Aschers.The relationship between the developmental stage of pistil and stamen and the size of bud were analysed to further study the molecular mechanisms of the double flower.The results showed that the form of host megaspore development was fritillaria typed embryonic.The anthers of the fertile line had four microsporangiates and the tapetum was belonged to the glandular type.Consecutive cytokinesis in microspore mother cell accompanies meiosis to produce tetrahedral tetrad.The mature pollen is 3-cellular type with two small sperms and one big vegetative cell.