Objective:To survey the expression of MMP-1,MMP-2 of human periodontal ligament cells(HPDLCs)treated by tea polyphenols(TP)and lipopolysaccharide(LPS).Methods:HPDLCs were in vitro cultured in vitro and treated by TP(200 μg/ml) and /or LPS(100 μg/ml)for 24,48 and 72 h respectively,the secretion of MMP-1 and MMP-2 were examined by ELISA,MMP-1 and MMP-2 mRNA expression was examined by real-time PCR.Results:The secression and mRNA expression of MMP-1 and MMP-2 of HPDLCs increased by LPS treatment and significantly inhibited by TP at the different times.Conclusion:TP can inhibit the col-lagen degradation of HPDLCs mediated by LPS.