Enhancing soil organic carbon(SOC)storage is one of the natural solutions to addressclimate change,but frequent forest fires increase its uncertainty and challenges.To elucidate the temporaland depth-dependent dynamics of SOC density under fire disturbance and identify the primary drivers,0~20 cm soil samples of Pinus tabuliformis forests in Beijing were collected and analyzed multiple times over2 years post-fire to accurately predict soil carbon sequestration potential and its response and feedback toclimate change.The results showed that:1) Over a two-year period,the SOC density in post-fire topsoil (35.22±7.53) t/hm²decreased significantly by 21.53%compared to the control plot (44.88±3.97) t/hm²,and the monthly variation in the fireaffected plot was more pronounced than in the control,with a 12.49%higher coefficient of variation.Post-fire SOC density declined significantly over time,and its disparity from controls increased annually.2) Similar to the controls,post-fire SOC density decreased with increasing soildepth:0~5 cm(12.22±0.58) t/hm²>5~10 cm(9.11±0.27) t/hm²>10~15 cm(7.28±0.36) t/hm²>15~20 cm(6.60±0.57) t/hm².The differences from the controls also diminished with depth.However,thepost-fire monthly dynamics of organic carbon density at different depths were more complex.3) Structuralequation model indicated that SOC density was directly affected by fire disturbance and soil depth,exhibi-ting stronger negative effects(β=-0.508～-0.575) than the direct positive effects(β=0.096～0.327) offactors such as bulk density and nutrients.In contrast,time mainly indirectly affected organic carbondensity by affecting aggregate fractions,resulting in an overall weak negative influence(β=-0.054).