Dental　pulp　stem　cells　(DPSCs)　are　stem　cells　present　in　the　dental　pulp　and　have　same　renewal　and　differentiating　properties　as　bone　marrow　cells.　Hence,　DPSCs　can　be　used　for　future　regenerative　therapies　of　various　diseases.　Previous　studies　show　that　DPSCs　would　lose　their　differentiation　capability　during　long-term　passage　when　they　were　cultured　in　medium　promoting　differentiation.　Researchers　have　been　working　to　explore　the　key　genes　that　influence　their　differentiation　capability.　However,　the　differentiation　of　dental　pulp　stem　cells　is　accompanied　by　a　complex　biological　process　involving　multiple　genes　and　multi-element　interactions.　In　this　study,　we　used　the　weighted　gene　co-expression　network　(WGCNA)　to　obtain　gene　network　modules　based　on　a　gene　microarray　data　set　from　a　DPSCs　experiment,　which　is　available　at　the　Gene　Expression　Omnibus　(GEO)　public　database.　We　identified　two　modules　(yellow　module　and　salmon　module)　significantly　associated　with　DPSC　passage.