Abstract: Understanding the effect of temperature on the demographic characteristics and predation rate of a predator on the target pest is crucial for an effective biological control. In this study, the life table and predation rate of Arma custos reared on Ectropis grisescens were studied at three temperatures (22, 26, and 30 ℃). The raw data were analyzed based on the age-stage, two-sex life table theory. The preadult duration and total preoviposition period (TPOP) were significantly shortened at higher temperatures. Although there were no significant differences in the mean fecundity and the net reproductive rate among three temperatures, the intrinsic rate of increase (r) and finite rate of increase (λ) at 26 °C (r = 0.0549 d-1, λ = 1.0565 d-1) and 30℃ (r = 0.0609 d-1, λ = 1.0628 d-1) were significantly higher than those at 22 ℃ (r = 0.0281 d-1, λ = 1.0285 d-1). The highest net predation rate (C0 = 73.95 prey/predator) observed at 26℃ was significantly greater than that at 22°C (C0 = 47.92 prey/predator) and 30 °C (C0 = 39.63 prey/predator). There were no significant differences in the transformation rate (Qp), the stable predation rate (ψβ) and the finite predation rate (ωβ) among the three temperatures. Computer simulation indicated that population growth and predation potential were higher at 26 and 30 °C than at 22℃. In order to optimize the release strategies and the control efficacy using A. custos against E. grisescens, field trials are needed to consider the possible differences between data collected under the laboratory condition and actual tea plantations.