Monitoring　vegetation　photosynthesis　in　China＇s　subtropical　regions　using　remote　sensing　is　challenging　because　of　the　complex　ecosystems　and　climate　variability.　Previous　studies　often　pay　less　attention　on　the　influence　of　multiple　climatic　factors　on　the　temporal　effects　(lag　and　accumulation)　of　vegetation　photosynthesis,　thereby　underestimating　their　impact.　This　study　utilizes　a　dataset　comprising　Solar-induced　chlorophyll　fluorescence　(SIF)　data　(GOSIF　product),　MODIS　Land　Cover　product　(MCD12C1),　and　various　climatic　variables.　Analytical　methods　including　Theil-Sen　Median　trend　analysis,　the　Mann-Kendall　test,　partial　correlation　analysis,　and　the　optimal　parameter-based　geographical　detector　(OPGD)　model　were　employed　to　explore　the　temporal　dynamics　of　subtropical　vegetation　SIF　responses　to　climatic　factors　and　to　identify　their　climate　drivers　in　subtropical　China.　The　study　findings　indicate　that　(1)　vegetation　photosynthesis,　as　indicated　by　SIF,　exhibited　an　increasing　trend　in　the　majority　of　Chinese　subtropical　regions,　which　constitute　over　80　%　of　the　study　area,　with　particularly　pronounced　enhancements　in　the　southern　and　central　western　parts　of　the　Chinese　subtropics.　(2)　Soil　moisture　primarily　exhibits　lag　effects　on　SIF,　particularly　in　evergreen　needleleaf　forests,　deciduous　broadleaf　forests,　and　mixed　forests,　whereas　temperature　does　not　exhibit　significant　temporal　effects.　Solar　radiation　and　vapor　pressure　deficits　impact　SIF　through　both　lag　and　accumulation　effects.　Under　the　lag　and　accumulation　effects,　the　proportion　of　significant　correlations　between　climatic　factors　and　vegetation　SIF　increases　by　36.71　%　∼　43.8　%,　excluding　temperature.　(3)　Temperature　is　the　dominant　factor　affecting　vegetation　SIF,　particularly　in　the　evergreen　needleleaf　forest.　Interactions　between　climatic　factors　have　a　significantly　stronger　influence　on　SIF　than　individual　factors.　Notably,　the　explanatory　power　of　the　vapor　pressure　deficit　increases　substantially　when　it　interacts　with　other　factors.　Studying　the　lag　and　accumulation　effects　of　climatic　factors　on　photosynthesis　aids　in　accurately　predicting　vegetation　responses　to　climate　change,　thereby　improving　the　accuracy　of　global　carbon　cycle　models　and　guiding　the　development　of　carbon　sequestration　management　strategies.　©　2024　The　Author(s)