Background.　Collagen　I　(Col-I)　and　matrix　metalloproteinase-1　(MMP-1)　have　been　implicated　in　the　regeneration　and　remodeling　of　the　periodontium.　Studies　have　shown　that　enamel　matrix　proteins　(EMPs)　and　mechanical　stimuli　can　promote　the　synthesis　and　degradation,　respectively,　of　Col-I　and　MMP-1.　However,　the　effects　of　the　combination　of　EMPs　and　mechanical　stimuli　on　human　periodontal　ligament　are　not　known.　Objective.　Our　aim　was　to　test　the　combined　effects　of　EMPs　and　mechanical　stimuli　on　the　proliferation　of　human　periodontal　ligament　fibroblasts　(HPDLFs)　and　Col-I　and　MMP-1　mRNA　expression.　Methods.　Primary　HPDLFs　were　isolated　using　an　enzyme　digestion　method.　To　select　the　optimum　EMP　concentration　and　the　optimum　magnitude　and　loading　time　of　mechanical　stimuli,　HPDLFs　were　stimulated　with　gradient　concentration　of　EMPs　(0　mu　g/mL,　25　mu　g/mL,　50　mu　g/mL,　100　mu　g/mL　and　200　mu　g/mL)　and　mechanical　stimuli　(0　kPa,　25　kPa,　50　kPa,　100　kPa,　and　200　kPa　for　0　h,　3　h,　6　h,　12　h,　and　24　h),　respectively.　The　cell　proliferative　response　was　tested　by　the　MIT　assay.　The　impact　of　EMPs　combined　with　mechanical　stimuli　on　Col-I　and　MMP-1　mRNA　expression　were　measured　by　reverse　transcription　polymerase　chain　reaction.　Results.　100　mu　g/mL　of　EMPs　and　a　50　kPa　mechanical　stimulus　were　chosen　as　the　optimum　parameters　due　to　the　higher　proliferation　rates　than　other　doses.　The　combination　of　100　i4g/mL　of　EMPs　and　a　50　kPa　mechanical　stimulus　significantly　stimulated　HPDLFs　proliferation　and　increased　Col-I　and　MMP-1　expression　levels　compared　with　incubation　with　two　factors　alone.　Conclusions.　We　concluded　that　the　combination　of　EMPs　and　mechanical　stimulus　have　synergistic　effects　on　cell　growth,　cell　number,　collagen　turnover,　and　periodontium　remodeling.