〔Abstract〕 Objective To explore the effects of different phenotypes macrophages(Mφs) on the proliferation, migration and osteogenic differentiation of periodontal ligament stem cells(PDLSCs). Methods PDLSCs were isolated and cultured by tissue block method. Tohoku Hospital Pediatrics-1(THP-1) cell line was stimulated to activate into unpolarized Mφs(M0), then induced to polarize into type I Mφs(M1) and type II Mφs(M2). Quantitative real-time PCR(qPCR) detected the inflammatory factors tumor necrosis factor α(TNF-α), interleukin(IL)-1β, IL-6, IL-10 and transforming growth factor-β(TGF-β) mRNA expression level. After collecting culture supernatants with different phenotypes, PDLSCs were stimulated, native control(NC) group did not receive the culture supernatant of Mφs. The effects of PDLSCs proliferation were assessed via Methylthiazolyldiphenyl-tetrazolium bromide(MTT) assay, while scratch assays were employed to evaluate their migration. Western blot was utilized to analyze the protein expression of Runt-related transcription factor 2(RUNX2) and alkaline phosphatase(ALP). Additionally, Alizarin Red staining was performed to investigate the deposition of calcified nodules in PDLSCs. Results qPCR showed the relative expression of TNF-α, IL-1β and IL-6 in M1 Mφs were higher than those in M0 and M2 Mφs(P<0.05),and the relative expression of IL-10 and TGF-β in M2 Mφs were higher than those in M0and M1 Mφs(P<0.05); Western blot showed the expression of RUNX2 and ALP proteins in PDLSCs in M0 and M2 groups was higher than those in the NC group(P<0.05),Alizarin Red staining showed increased calcified nodule deposition in PDLSCs in M0,M1 and M2 groups compared to the NC group; MTT assay showed the proliferation of PDLSCs in the M0 and M1 groups was suppressed compared to the NC group(P<0.05); and scratch experiment showed the migratory capacity of PDLSCs in the M1 and M2 groups was stronger than that in the NC group. Conclusion M0 and M1 Mφs inhibit PDLSCs proliferation,M1 and M2 Mφs promote PDLSCs migration,and all types of Mφs promote osteogenic differentiation of PDLSCs.