Packed soil core incubation experiment was made to study the effects of external carbon (C) (glucose, 6.4 g C/m²) addition on microbial respiration and microbial biomass C (MBC) in soils of a mature broadleaf and Korean pine mixed forest (BKPF) and an adjacent white birch forest (WBF) during thaw under different soil moisture levels (55% and 80% water-filled pore space) and nitrogen (N) supply (NH₄Cl and KNO₃, 4.5 g N/m²). The results showed that, without C and N addition, cumulative CO₂ flux from the WBF soil was significantly higher than that from the BKPF soil during the incubation period. With increasing soil moisture, the cumulative CO₂ flux and microbial metabolic quotient (q_CO2) decreased in the WBF soil but increased in the BKPF soil without C and N addition(P < 0.05). The glucose-induced cumulative CO₂ fluxes from the two forest soils ranged from 9.61 to 13.49 g CO₂-C/m², which was greater than the dose of added C in the form of glucose. The glucose-induced MBC in the two forest soils ranged from 3.65 to 27.18 g C/m², while glucose addition had little impact on soil dissolved organic C pool. Hence, the extra C released upon addition of glucose may result from the decomposition of soil native organic C. Without N addition and under the two soil moisture levels, the glucose-induced cumulative CO₂ flux from the BKPF soil was significantly higher than that from the WBF soil during thaw (P < 0.001). With increasing soil moisture, the glucose-induced cumulative CO₂ fluxes from the two forest soils were significantly increased (P < 0.001). The addition of KNO₃ alone significantly increased the glucose-induced cumulative CO₂ flux (P < 0.01) and the glucose-induced MBC (P < 0.001) in the WBF soil under two soil moisture levels (P < 0.001). Addition of NH₄Cl alone significantly increased the glucose-induced MBC in the BKPF soil with low moisture level. Based on the results from the previously reported non-freezing experiments and the results of the present study, it can be concluded that freezing treatment significantly affects the stimulating effects of glucose on soil microbial respiration and MBC under temperate forests. Regardless of whether freezing occurred or not, the responses of soil microbial respiration and MBC to the addition of extraneous C as glucose in temperate forests depend on vegetation type, soil moisture, and the amount and type of N added.