The mechanism of pollen abortion of Dianthus caryophyllus was studied under low temperature environment in winter for further research hybrid breeding.Microsporogenesis process of male sterile was histologically examined using squash technique and paraffin embedded method.The results demonstrated:(1)only few mature pollen grains in winter was followed through the initiation of the microsporocyte formation,meiosis and the tetrad developmental period,finally formed pollen.(2)61% pollen mother cells aborted in 1.5-1.6 cm of buds and 71% pollen mother cells aborted in 1.7-1.8 cm of buds.(3)Furthermore,the portion of callose of tetrad could not dissolve resulting in microspores unreleased into the chamber.In brief,abnormal pollen mother cell and tetrad are the main cause of microspore in low temperature of winter.