Objective: To investigate the selective effect of Xihuang Pill on-estrogen receptor status of breast cancer. Method: Thirty estrogen-dependent breast cancer patients and 30 non-estrogen-dependent breast cancer patients were respectively randomLy assigned to two groups by digital table. The estrogen-dependent breast cancer patients used Letrozole 2.5 mg·qd. for 30 d and the treatment one was added with Xihuang Pill 3 g

bid for 30 d. The treatment group of non estrogen-dependent breast cancer patients were treated with Xihuang Pill. All the patients were observed their Traditional Chinese Medicine (TCM) syndrome

quality of life and tumor mark of breast cancer (CA50

CEA

CA153s)as well. MTT assay was used to assessed the viability of human breast cancer cell lines MCF-7 and MDA-MB-231 submitted to Xihuang Pill drug serum. Result: The treatment group and control group of estrogen-dependent breast cancer patients in improvement of quality of life was respectively 60%

40% (P<0.05)

and the total improvement rate of TCM syndrome was respectively 73.3%

53.3% (P<0.05). While the non estrogen-dependent one quality of life was respectively 46.7%

33.3%(P<0.05)

and the total improvement rate of TCM syndrome wais respectively 66.7%

46.7% (P<0.05). The CA153 values of treatment group and the control group of estrogen-dependent breast patients had a significant difference (P<0.05). Xihuang pill drug serum slightly decreased MCF-7 proliferation in the serum concentrations of 6.25%-25% in vivo

but promote proliferation of MDA-MB-231 instead. Conclusion: Xihuang pill had attenuated synergistic effect on estrogen-dependent breast cancer combined with Letrozole. And the curative effect was better than that of non-estrogen-dependent breast cancer

which showed its selective effect.