AIM:To study the effects of pentoxifylline(PTX)on thecontent of hepatic TGF-β1,type Ⅰ and type Ⅲ collagen inschistosomiasis japonica mice with liver fibrosis and itsmechanism of anti-fibrosis.METHODS:Forty mice with schistosomiasis were dividedinto four groups:one group as control without anytreatment,other three were treated with Praziquantel 500mg/(kg·d)for 2 d,high dose PTX 360 mg/(kg·d)for 8 wk,and low dose PTX 180 mg/(kg.d)for 8 wk respectively.Immunohistochemical technique and multimedia colorpathographic analysis system were applied to observe thecontent change of hepatic TGF-β1,type Ⅰ and type Ⅲcollagen in schistosomiasis japonica mice with liver fibrosisbefore and after PTX treatment.RESULTS:Effects of PTX on the content change of hepaticTGF-β1,type Ⅰ and type Ⅲ collagen in schistosomiasis japonicamice with liver fibrosis were related to the dosage of PTX,high dose PTX treated group could significantly reduce thecontent of TGF-β1(0.709±0.111),type Ⅰ(0.644±0.108)andtype Ⅲ(0.654±0.152)collagen compared with those ofcontrol group(0.883±0.140,0.771±0.156,0.822±0.129)with statistical significance(P<0.05).Low dose PTX couldalso reduce the hepatic content of TGF-β1(0.752±0.152),type Ⅰ(0.733±0.117)and type Ⅲ(0.788±0.147)collagen,but without statistical significance(P>0.05).Both high doseand low dose PTX groups have significant differences onthe content of TGF-β1,type Ⅰ and type Ⅲ collagen(P<0.05,P<0.05,P<0.01,respectively).CONCLUSION:High dose of PTX treatment could reducethe content of hepatic TGF-β1,type Ⅰ and type Ⅲ collagensignificantly in schistosomiasis japonica mice with liverfibrosis,and thus plays its role of antifibrosis.