Abstract: Objective　To observe the effect of Astragalus membranaous on angiotensin Ⅱ (Ang Ⅱ)-induced transforming growth factor β1 (TGF-β1) production of cardiac fibroblasts. Methods  Cardiac fibroblasts were cultured in vitro. Cells were allocated into 3 groups: control group, Astragalus membranaous groups (50, 100, 200 mg/ml), Ang II group (10-7 mol/L) and AngⅡ/Astragalus membranaous groups (50, 100, 200 mg/ml). The proliferation of each group was tested by methyl thiazolyl tetrazolium method. TGF-β1 was measured by ELISA. Results  The proliferation of cardiac fibroblasts had significant difference between each groups (F=71.84, P=0.000). The proliferation of cardiac fibroblasts with Ang II stimulation was higher than that of cells without Ang II stimulation (P<0.05). Astragalus membranaous inhibited Ang II-induced cardiac fibroblasts proliferation dose dependently (P<0.05). The TGF-β1 production had significant difference between each groups (F=786.81, P=0.000). The TGF-β1 production in AngII/astragalus membranaous groups was lower than that in Ang II group (P<0.05). The TGF-β1 production in Ang II group was the highest, and had significant difference as compared to other groups (P<0.05). Astragalus membranaous inhibited Ang II-induced TGF-β1 production dose dependently (P<0.05). Conclusions  Ang II can stimulate the proliferation of cardiac fibroblasts, and promote the TGF-β1 production. Astragalus membranaous can inhibit the proliferation of Ang II-induced cardiac fibroblasts, and reduce the TGF-β1 production of cardiac fibroblasts.