To investigate the diurnal variation and seasonal variation characteristics of soil respiration rate in north subtropical deciduous broad-leaved forest,the soil respiration rates in Longwang Mountain forest of Nanjing,Jiangsu province were measured using LI-8100 automated soil CO₂ flux system,and the soil temperature and moisture were recorded at the same time.The result showed that soil respiration rate increased and reached its peak during 12:00 to 14:00,which is generally in accordance with the diurnal change of soil temperature.As for the seasonal variation,the forest soil respiration rate changed with the seasonal variation of soil temperature.The soil respiration rate was relatively high when the soil temperature was high in summer,and vice versa.Significant relationship was found between soil respiration rate and soil temperature,and the Q₁₀ of deciduous broad-leaved forest soil in Longwang Mountain was calculated to be 2.81.