Abstract: The present study consists of the cytological observations on the process of microsporogenesis and pollen development in the regenerated stamen of hyacinth; and a comparative study of the cytological changes in stamens of both regenerated and produced under natural condition. Results showed that the cytological changes of microsporogenesis and the pollen deveLopment in the regenerated stamen of the hyacinth were basically normal. But in the stage of the mature pollen there was an obvious cytological difference between both stamens in vitro and in nature. The mature pollen of the regenerated stamen consisted of three cells: one vegetative cell and two sperms, while mature pollen grain under natural condition was made up of two cells: one vegetative cell and one generative cell. This difference mainly resulted from different time and place of the generative cell division. The reason resulting in the differences and their influence on sperms were discussed.

Key words: Hyacinthus orientalis L., Microsporogenesis, Pollen development