In order to investigate the influence of interleukin 1?(IL 1?) and tumor necrosis factor ? (TNF ?) on gene expression of rat interstitial collagenase (MMP 13 ) in hepatic stellate cells, cells of a hepatic stellate cell line (HSC T6) were cultured in medium containing IL 1? or TNF ? for different incubation periods. Total RNA of HSC was extracted and MMP 13 gene expression levels were measured by reverse transcription polymerase chain reaction. The results showed that MMP 13 gene expression level of the IL 1? group was much higher than that of the control group at 8h, 24h and 48h after exposure to IL 1?. The maximal value was 3 fold of the control group and was at 24h . MMP 13 gene expression level of the TNF ? group was also significantly higher than that of control group at 8h, 24h, 48h, 72h, and the maximum nalue was 4 fold of the control group at 48h. These results indicated that IL 1? and TNF ? might increase the gene expression of MMP 13 in hepatic stellate cells.