We　investigated　the　effects　of　millimeter　wave　treatment　on　the　expression　of　the　cell　cycle　regulating　proteins　cyclin-dependent　kinase　2　(CDK2)　and　cyclin　A　in　chondrocytes.　Knee　articular　cartilage　from　SD　rats　was　used　to　establish　cultured　primary　chondrocytes.　After　identification　using　toluidine　blue　staining,　passage　2　chondrocytes　were　randomly　divided　into　different　groups　and　treated　with　nocodazole　or　millimeter　wave.　The　RNA　expression　of　CDK2　and　cyclin　A　was　measured　using　RT-PCR,　and　their　protein　levels　were　detected　by　Western　blotting.　Cell　cycle　analysis　showed　that　nocodazole　treatment　significantly　increased　the　number　of　G0/G1　and　G2/M　stage　chondrocytes　and　decreased　the　amount　of　S　phase　cells.　In　contrast,　millimeter　wave　treatment　significantly　decreased　the　number　of　G0/G1　and　G2/M　chondrocytes　and　increased　the　number　of　S　phase　cells.　The　mRNA　and　protein　levels　of　CDK2　and　cyclin　A　consistently　demonstrated　a　reverse　trend,　with　the　lowest　levels　in　the　chondrocytes　treated　with　nocodazole.　The　expression　of　CDK2　and　cyclin　A　was　higher　in　chondrocytes　receiving　millimeter　wave　treatment　than　in　untreated　cells.　In　conclusion,　millimeter　wave　treatment　induces　CDK2　and　cyclin　A　expression,　accelerates　S-phase　entry　and　G2/M　transition　and　promotes　chondrocyte　cell　cycle　progression.