Abstract: To evaluate the influence of different host plants including apple, wild jujube, jujube, pear and hawthorn on the coldtolerance substances in overwintering larvae of the peach fruit moth Carposina sasakii Matsumura, we measured the larvae supercooling capacity, the water content (W), total fat content (TFC), total protein content (TPC) and total glycogen content (TGC) in the body. Results showed that the mean  supercooling point (SCPs) and  freezing point (FPs) of overwintering larvae from the 5 host plant fruits differed significantly, ranging from -15.53 to -8.50 ℃ and -11.31 to -4.04 ℃, respectively. The overwintering larvae fed on hawthorn owned the highest SCP, FP, TGC and the lowest W, while those fed on apple had the lowest SCP, FP, TFC and TGC but the highest W and TPC. The fresh mass (FM) of the overwintering larvae fed on pear was the highest, while those fed on jujube was very low. Those fed on jujube accumulated the highest TFC but the lowest TPC.