Abstract: Objective: to investigate the feasibility of primary culture of nontumorigenic human mammary epithelial cells, and the effect of proliferation due to hormone. Method: Normal human mammary tissue was taken from mammary segment ectomy, and the tissue were digested by collagenase type Ⅰ. Epithelial depuration was carried out by integration of burning and enzyme digestion. The cells we acquired were identified by observation of cell morphology by light and Transmission Electron Microscopy (TEM). Result: We found it is feasible to culture nontumorigenic human mammary epithelial cells. Conclusion:β-estradiol and progesterone at 1×10-5g/L can promote the proliferation of the normal human mammary epithelial cells.