Objective To afford an effective method to determine the ovulatory phase in female Macac a fascicularis for its artificial insemination and hybridization. Meth od 30 female Macaca fascicularis at the age of 4-6 years were selec ted to assess the changes of various types of cells in vaginal smears. R esult and Conclusion The major cell types in the Macaca fascicularis vaginal smears included leucocytes, keratinized epithelial cells, intermediat e and basal cells and cell debris. The amount of leucocytes is significantly dif ferent in various phases of the menstrual cycle(p<0.05). The number of kerat inized epithelial cells is the same in both preovulatory and menstrual phases, but is significantly(p< 0.05) different in other phases of the menstrual cycle. There is no significant dif ference in the number of intermediate and basal cells at menstrual and postovula tory phases, but is significantly(p<0.05) different in other phases of the m en strual cycle. The amount of cell debris is similsr to that of keratinized epithe lial cells. The changes of cells profile in various phases were that the number of keratinized epithelial cells increased gradually to tiptop from menstrual pha se to ovulatory phase and then reduced gradually, but the changes of leucocytes, intermediate and basal cells and cell debris are contrary to that of keratinize d epithelial cells.