[Aim] Spalangia endius Walker (Hymenoptera:Pteromalidae) is a pupal parasitoid of numerous dipteran pests. Understanding the effects of temperature on parasitic efficiency is critical in utilizing them in pest control.[Method] Laboratory studies were carried out to determine the parasitization potential of female S. endius on the pupae of melon fly Bactrocera cucurbitae (Coquillett) (Diptera:Tephritidae) under five constant temperatures (21℃, 24℃, 27℃, 30℃, 33℃). Attack responses of S. endius on melon fly were described by a Michaelis-Menten type Ⅱ model N_a=AN/(F+N).[Result] Both parasite potential (A) and half saturated host density (F) were influenced by temperature. The maximum parasite potential was registered at 27℃, whereas half saturated host density decreased with increasing temperature.[Conclusion] The optimal temperature was similar to temperature in the habitat in the melon field, indicating parasitoid adaptation.