Abstract: On the basis of eddy covariance technique and flux data from June, 2016 to May, 2017, the characteristics of carbon flux in the mixed broadleaf-conifer forest ecosystem in Jinyun Mountain and its response to environmental factors are analyzed. The results show that the mean inteRdiuRnal variation of monthly CO2 flux presented a “U” shape during the study, and the minimum value is -0.95 mg·m ^-2·s ^-1 in July and the maximum value is 0.43 mg·m ^-2·s ^-1 in December. Moreover, there is obvious seasonal variation in the transition time of CO2 flux positive and negative values, among them, the time of daily carbon sink is the longest in summer and the shortest in winter; the NEE cumulant is negative and presented as carbon sink in 12 months of one year except December, in which is positive (20.38 gC·m ^-2·mon^-1) and presented as carbon source, the largest carbon accumulation is in July (-129.53 gC·m^-2·mon_-1), NEE, ER and total GEE are -566.49, 1 196.68 and -1 761.63 gC·m^-2·a^-1·respectively.Furthermore, PAR is the dominant factor affecting the NEEd, the relationship between them is consistent with the Michaelis-Menten model, NEEd decreases with the increase of PAR, and PAR can explain the change NEEd of 14.1%-58.2%; VPD is the limiting factor of NEEd, whose optimal range is 0.5-1 kPa, because too high or too low will reduce the response of NEEd to PAR; 5cm Ts is the dominant factor affecting NEEn,the relationship between them is consistent with the Van’t Hoff model, and NEEn increases with the increase of 5 cm Ts; SWC is the limiting factor of NEEn, when SWC is greater or less than 0.28 m-^3·m^-3, it will inhibit the NEEn with little effect. To sum up, the NEE capacity of mixed broadleaf-conifer forest in Jinyun Mountain is basically equal to that of other forest ecosystems at similar latitudes, while the total ecosystem exchange capacity and ecosystem respiratory intensity are larger.