Objective To discuss the possible mechanism of Wenyang Huazhuo Tongluo Formula（ WYHZTLF）in the treatment of systemic sclerosis（ SSc）. Methods In total 60 C3 H / He mice were randomly divided into normal group

model group

western medicine group and the low

medium and high dose TCM groups

with 10 in each.Except for the normal group

all groups were injected with bleomycin subcutaneously for 3 weeks to make the SSc mouse model. The western medicine group was given penicillamine tablets 65 mg /（ kg·d） by gavage

while the low

medium and high dose TCM groups were given 11. 75 g /（ kg·d）

23. 5 g /（ kg·d）

or 47 g /（ kg·d） of WYHZTLF decoction respectively

and the model group and normal group were given the equal volume of saline. Treatments for all groups lasted for 8 weeks. Pathological changes of skin tissues were observed using HE staining. The expression of skin transforming growth factor-β1（ TGF-β1）

Smad 2 and Smad 7 mRNA

type Ⅰ and Ⅲ collagen（ COL-Ⅰ

COL-Ⅲ） in the skin was tested. Results The dermis of the model group was thicker than the normal group

with more and thicker collagen

as well as infiltration of inflammatory cells around small vessels

while the western medicine group and all TCM groups showed thinner dermis compared with the model group

with less collagen content and infiltration of inflammatory cells. Compared with the normal group

the expression of TGF-β1

Smad 2 mRNA

COL-Ⅰand COL-Ⅲ protein in the model group increased

while the expression of Smad 7 mRNA decreased（ P < 0. 01）.Compared with the model group

the expression of TGF-β1

Smad 2 mRNA

COL-Ⅰ and COL-Ⅲ in the western medicine group and all TCM groups decreased

while the expression of Smad 7 mRNA increased（ P < 0. 05 or P <0. 01）. Improvements on the expression of TGF-β1

Smad 2

Smad 7 mRNA

COL-Ⅰ and COL-Ⅲ in high dose TCM group was better than that in the western medicine group and low dose TCM group（ P < 0. 05 or P < 0. 01）.Conclusion WYHZTLF could antagonize the fibrosis in SSc

which could be related to its regulation of TGF-β1 /Smad signal pathway and reduction of collagen content. This effect of WYHZTLF is better when dose is high.