The functional and numerical responses of an important predator Mallada besalis Walker feeding on Corcyra cephalonica eggs were respectively carried out in laboratory. The results showed that the functional response conformed to Holling Type II equation. In a certain range, the predation of M. besalis larvae increased with an increase of the prey's density then tended to be a steady value. it was also related to whether there was water supply。When water was supported, the theoretical predation of the 3rd instar larvae was largest, it was 3205.1 C. cephalonica eggs per day.The results of numerical response research showed that the growth, development and reproduction of M. besalis larvae were significantly influenced by C. cephalonica egg's density.The developmental rate, female fecundity, hatching rate, female ratio of M. besalis larvae, and adult longevity increased with an increase of C. cephalonica egg' density, then tended to be steady. The C. cephalonica egg's density threshold for larvae survival, larvae pupation, adult emergence, offsping eggs hatching and population maintenance were respectively 5, 10, 20, 30 and 50 eggs per day. In the research of natural enemy large-scale breeding and control potential against pest, numerical response emphasized on the dependence of predators on prey density and the prey density thresholds would cause predator population to decline. This would provide theoretical basis for fodder allotment, cost control and enhanced the predator's capability of controlling pest when alternative host was added in field. It would be concluded from the above results that M. besalis has potential value to be considered as a biological control agent. And we discussed the importance and emphasis of functional and numerical responses in the natural utilization.