OBJECTIVE： To study the inhibition effects of tranilast on hypertrophic scar tissue of rabbits and its mechanism. METHODS： Rabbits were selected to induce hypertrophic scar （HS） model， the HS model rats were randomly divided into model control group （normal saline）， tranilast low-dose， medium-dose， high-dose groups （0.3， 0.5， 0.7 mg/kg）， 6 rabbits in each group， local intradermaly injected corresponding drugs. Scar thickness 1 h before injection and the first， third， fifth week after injection in each group were measured， pathological changes of scar （fifth week after injection）were observed， transforming growth factor β1  （TGF-β1）， α-smooth muscle actin （α-SMA） mRNA and protein expression were detected. RESULTS： Compared with 1 h before injection， scar thickness of rabbits in other groups were decreased after injection except for model control group. In fifth week after injection， compared with model control group， scar thickness of rabbits in other groups were decreased， pathological changes were improved； TGF-β1， α-SMA mRNA and protein expression were decreased （P＜0.05）， showing positive correlation with tranilast dose. CONCLUSIONS： Tranilast can inhibit the formation of hypertrophic scar， and the mechanism may be related to inhibiting the TGF-β1， α-SMA mRNA and protein expression.