By the method of SEM, it is observed succesively in the process of strobilis formation of Pinus massoniana that the change of stem apex and the fermed of floral primordium.The result showed that there are a few plants only formed female strobil or male strobil.The starting period and the change of phenology of Pinus massoniana is not the same in different regions. It appears earlier in the region of low latitude and high temperature than that in the region of high latitude and low temperature.