Abstract: Objective To explore the effects of diethy lstilbestrol on the expression of the WISP-2 gene in human breast cancer cell line MCF-7,and its mechanism.Methods To detect the proliferation by using MTT method.The expression of WISP-2 mRNA and its protein were measured using RT-PCR and immunohistochemistry approcah.The experiment set up 17-B estradiol as positive control.Results Diethy lstilbestrol accelerated the M CF-7 cell proliferation,the value of A570 obviously raised as the time raised,compared with control(P<0.05);The expression on WI SP-2 mRN A and its protein was increased,the difference had significance.And the effect was increased after exposed to diethylstilbestrol for more time.The expression of WI SP-2 gene was increased,the difference had significanc.Its effects was similar to 17-B estradiol.Conclusion Diethylstilbestrol can accelerate the MCF-7 cell proliferation.Diethylstilbestrol can induce the expression of WISP -2 gene in the MCF-2 cell.Its effects was increased when concentr ation was increased with time growing.