Objective: To observe the effects of transforming growth factor-β1 (TGF-β1) and atorvastatin on expressions of collagen type I P-Smad2, Smad4 and Smad7 in human atrial ifbroblasts, and to explore the ifbrosis and anti-ifbrosis mechanisms in human atrium. Methods: Human right atrial appendage tissue was obtained from the cardiac surgery in our hospital and the atrial ifbroblasts were isolated and cultured by generations. The effects of TGF-β1 and atorvastatin on atrial ifbroblast proliferation was detected by MTT method and the effect of TGF-β1 at (0, 0.1, 1.0, 5.0, 10.0, 20.0, 50.0) ng/ml and atorvastatin at (0, 0.1, 1.0, 10.0, 100.0) μmol/L on mRNA and protein expressions of collagen type I P-Smad2, Smad4 and Smad7 in atrial ifbroblasts were examined by RT-PCR and Western-blotting analysis respectively. Results: MTT detection presented that compared to TGF-β1 at 0 ng/ml, with the intervention of TGF-β1 at (1 and 10) ng/ml, the mRNA and protein expressions of collagen type I P-Smad2, Smad4 increased,P<0.05 and the expressions of Smad7 decreased,P<0.05. Compared to TGF-β1 at 10.0 ng/ml, with the intervention of TGF-β1 + atorvastatin at 10.0 μmol/L or with atorvastatin at 10.0 μmol/L alone, the mRNA and protein expressions of collagen type I P-Smad2, Smad4 decreased,P<0.05and expressions of Smad7 increased,P<0.05. Conclusion: TGF-β1 promotes human atrial ifbroblast proliferation and collagen type I expression, while atorvastatin inhibits such proliferation and expression, the effect might be done by affecting TGF-β1/Smads pathway in human atrial ifbroblasts.