Abstract: Soil CO₂ effluxes in natural broad-leaved forest and the conversed Chinese fir plantation in Linglong Mountains Scenic of Zhejiang Province were evaluated by using static closed chamber and gas chromatography method. The results showed that soil CO₂ efflux showed consistent seasonal dynamics in natural broad-leaved forest and Chinese fir plantation, with the maximums observed in summer and autumn, the minimums in winter and spring. Soil CO₂ effluxes were 20.0-111.3 and 4.1-118.6 mg C·m^-2·h^-1 in natural broadleaved forest and Chinese fir plantation, respectively. The cumulative soil CO₂ emission of natural broadleaved forest (16.46 t CO₂·hm^-2·a^-1) was significantly higher than that of Chinese fir plantation (11.99 t CO₂·hm^-2·a^-1). Soil moisture did not affect soil CO₂ efflux. There was a significant relationship between soil CO₂ efflux and soil temperature at 5 cm depth. There was no significant relationship between soil CO₂ efflux of natural broadleaved forest and water soluble organic carbon content, while water soluble organic carbon content affected significantly soil CO₂ efflux in Chinese fir plantation. Converting the natural broadleaved forest to Chinese fir plantation reduced soil CO₂ efflux significantly but improved the sensitivity of soil respiration to environmental factors.