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A generalized, lumped-parameter ecological model PnET-CN was calibrated and validated for a subtropical coniferous plantation in southem China. PnET-CN model describes the biogeochemical cycles of carbon(C)and nitrogen(N)and can assist in estimating carbon sequestration potential. For validation of PnET-CN, data from coniferous forest plantations in southern China was used. Simulated daily gross primary productivity(GPP)from 2005 to 2007 agreed well with observations(R2=0.56, S.D.=0.009). Simulations of monthly soil res-piration(R3)from 2005-2007 agreed well with R8 observations(R2=0.67, S.D. =0.03). Simu-lated annual net primary productivity(NPP)from 1998-2006 was 803±33 gCm-2a-1, about 4% higher than NPP observation(752±51 gCm-2a-1). Simulations of annual NEP from 2005-2007 only overestimate 9 gCm-2a-1(4%), 4 gCm-2a-1(1%)and 34 gCm-2a-1(8%)compared to NEP observations, respectively. Simulated annual foliar N concentration(FolNCon)(1.09%)is 10% lower than observed monthly FolNCon(0.87%-1.58%). Simulated annual N leaching(0.26 gNm-2)is about 10% lower than leaching observation(0.29 gNm-2). PnET-CN model valida-tion indicates that PnET-CN is capable to simulate daily GPP, annual NPP, annual NEP, monthly R,, annual FolNCon and annual nitrate N leaching for subtropical coniferous planta-tions in southem China. The results obtained from the validation test revealed that PnET-CN model can be used to simulate carbon sequestration of planted coniferous forests in southern China to a high level of precision. Sensitivity analysis suggests that great care should be taken in developing generalizations as to how forests will respond to a changing climate. PnET-CN performed satisfactorily in comparison to other models that have already been calibrated and validated in coniferous planted subtropical forests in China. Based on PnET-CN validation and its comparison to other models, future improvement of PnET-CN should focus on seasonal foliar N dynamics and the effects of water stress on autotrophic respirations in subtropical coniferous plantations in southern China.