Peatland ecosystems play an important role in global carbon cycle. Peatlands may act as carbon source or carbon sink. This function transformation of carbon has become one of the topic issues of studies on global climate change. In order to study the characteristics of carbon flux and factors influencing carbon flux in Dajiuhu wetland (in Shennongjia Forestry Administrative District, Hubei province, China), we monitored CO_2 flux and environmental factors such as photosynthetic photon flux density(PPFD), air temperature (Ta), soil temperature (Ts) and soil water content (SWC) in a field station in Dajiuhu, and investigated variation patterns of CO_2 flux and analyze which environmental factors can affect CO_2 flux during the growing season (from June to August of 2016) and non-growing season (December 2015 to February 2016). The results showed that: (1) The average diurnal variation of CO_2 flux in growing season demonstrated a U-type curve, range from -6.84 to 6.65 mumol·m~(-2)·s~(-1). In non-growing season, diurnal CO_2 flux ranging from -0.88 to 5.19 mumol·m~(-2)·s~(-1). (2) The relationship between the daytime CO_2 flux and photosynthetic photon flux density (PPFD) could be fitted by rectangular hyperbola models in the both growing and non-growing season. However, the fitted curve in the growing season (R2=0.427 3, P<0.01) had a better goodness of fitting than that of the non-growing season(R2=0.045 6, P<0.01). (3) In the growing season, relationship between CO_2 flux and air temperature (Ta) could be described as an aquadratic curve (R2=0.248 6, P<0.01), and the CO_2 flux first increased and then decreased when Ta increasing. The correlation between CO_2 flux and air temperature in non-growing season was significantly negative (R2=0.042 8, P<0.01), and the relationship is negative, but only 4.28% of the CO_2 flux variation could be explained by air temperature. (4) The influence of soil temperature (Ts) and soil water content (SWC) on CO_2 flux was mainly reflected in ecosystem respiration. SWC and Ts were the main factors that influenced nighttime ecosystem respiration in growing season, and the temperature sensitivity of the ecosystem respiration Q10 was 1.84. Nevertheless, in the non-growing season, the correlation between the nighttime ecosystem respiration and Ts (or SWC) was not significant (P>0.05).