Increasing global temperatures have accelerated the soil carbon cycle, greatly affecting the carbon dynamics in forest ecosystem. Warming also impacts the growth and metabolism of soil microorganisms, influencing the decomposition of organic matter, and then affects soil respiration. However, it remains unclear how soil microbial respiration responds to long-term soil warming in subtropical areas. In this study, we investigated the effects of long-term soil warming on soil carbon dynamics by measuring soil basal respiration and substrate-induced respiration. Soil samples were taken from a depth of 0-10 cm in control and warming (7years, +4℃) plots in August and December, respectively. Glucose solution or an equal volume of deionized water was added to the soil samples, with the original soil serving as the control. The soil was incubated at 25 ℃ for 4 hours, and soil basal respiration and substrate-induced respiration were measured to analyze the effects of warming on soil microbial respiration and microbial metabolic entropy (qCO₂). We found that: (1) Soil warming significantly decreased soil microbial biomass carbon (MBC) by 32.1% and 59.8% in August and December, respectively (P<0.05). (2) Soil warming did not significantly affect the response of the soil basal respiration and substrate-induced respiration, possibly due to the thermal adaptation of microorganisms. Moreover, after water supplementation, soil respiration in the warming and control plots significantly increased by 38.26% and 104.81% in August, compared to soil basal respiration. This increase suggests that soil moisture is a crucial factor affecting soil microbial respiration. After glucose supplementation, substrate-induced respiration significantly increased by 113.05% and 152.87% in August and 117.98% and 160.92% in December, respectively, indicating that substrate availability is another key factor affecting soil microbial respiration. (3) Soil warming increased microbial metabolic entropy by 127.7% in December, but there was no significant difference in August, which was related to the decrease in MBC. (4) Soil dissolved organic carbon and soil microbial biomass carbon were negatively correlated with microbial metabolic entropy, while showing a positive correlation with soil water content in both warming and control treatments (P<0.05). Our results suggested that after seven years of soil warming, carbon availability and the decrease in soil moisture are important factors affecting soil microbial respiration in subtropical Chinese fir plantations.