Objective To investigate the effect of Porphyromonas gingivalis lipopolysaccharide(LPS) on proliferation and inflammatory factors expression of human periodontal ligament stem cells(HPDLSCs).Methods HPDLSCs were cultivated and identified. Experiment was divided into 3 groups according to culture solution: Group A with α-MEM culture solution containing 10 μg•mL-1LPS, group B with supernatant fluid containing 10 ng•mL-1LPS stimulated mono-cyte, group C with α-MEM culture solution. The proliferation ability of HPDLSCs was analyzed by MTT assay. The ex-pression levels of interleukin-1β(IL-1β), interleukin-6(IL-6), tumor necrosis factor(TNF-α) mRNA of HPDLSCs were detected by reverse transcriptase polymerase chain reaction(RT-PCR).Results HPDLSCs had clonality, bone and fat differentiation ability. Compared with group C, the proliferation ability of HPDLSCs of group A and group B was sig-nificantly inhibited, and the proliferation ability of HPDLSCs of group B were more significantly inhibited than that of group A(PConclusion Porphyromonas gingivalis may inhibit the proliferation of HPDLSCs directly or indirectly through LPS and increase expression of inflammatory factor, exacerbate periodontal inflammatory tissue damage and delay the self-repairing of periodontal tissue.