Objective: To study the inhibitory effect of chuanxiongzine on vascular smooth muscle cell (VSMC) proliferation and explore its molecular biology basis. Methods: we selected the VSMC cultured 4~8 generation from rat aorta thoracalis as research object. The objects were divided into four groups(Ⅰ)control group,(Ⅱ)chuanxiongzine(50 μg/ml)group,(Ⅲ)chuanxiongzine (100 μg/ml) group and(Ⅳ) chuanxiongzine(200 μg/ml) group. The inhibitory effect of chuanxiongzine on VSMC proliferation was investigated by cell counting, MTT and 3H-TdR incorporation assay. In order to illuminate the molecular biology mechanism of chuanxiongzine inhibiting VSMCs proliferation, the expression of proliferating cell nuclear antigen(PCNA) and C-myc were detected. Results: Chuanxiongzine could inhibit the proliferation of VSMC significantly in a dose- and time-dependent manner, compared with control group (P < 0.05). The expression of PCNA and c-myc were inhibited obviously and correlated with the concentration of chuanxiongzine (P < 0.05). Conclusion: Chuanxiongzine may play a considerable role in VSMC proliferation process. The inhibitory effect of chuanxiongzine in a dose- and time-dependent manner can be realized via down regulating the expression of PCNA and c-myc. In this study, The great theoretical fundament about Chinese medicine, which is used to treat atherosclerosis(AS), has been obtained. Objective: To study the inhibitory effect of chuanxiongzine on vascular smooth muscle cell (VSMC) proliferation and explore its molecular biology basis. Methods: we selected the VSMC cultured 4 to 8 generation from rat aorta thoracalis as research object. The objects were divided into four (Ⅱ) chuanxiongzine (50 μg / ml) group, (Ⅲ) chuanxiongzine (100 μg / ml) group and (Ⅳ) chuanxiongzine (200 μg / ml) proliferation was investigated by cell counting, MTT and 3H-TdR incorporation assay. In order to illuminate the molecular biology mechanism of chuanxiongzine inhibiting VSMCs proliferation, the expression of proliferating cell nuclear antigen (PCNA) and C-myc were detected. inhibit the proliferation of VSMC significantly in a dose- and time-dependent manner, compared with control group (P <0.05). The expression of PCNA and c-myc were all displayed obviously and correlated with the concentra tion of chuanxiongzine (P <0.05). Conclusion: Chuanxiongzine may play a considerable role in VSMC proliferation process. The inhibitory effect of chuanxiongzine in a dose- and time-dependent manner can be realized via down regulating the expression of PCNA and c-myc In this study, The great theoretical fundament about Chinese medicine, which is used to treat atherosclerosis (AS), has been obtained.