Abstract: Predatory function responses of Menochilus sexmaculata female and male adults to Bemisia tabaci, Aphis craccivora and Rhopalosiphum maidis were measured in laboratory. Predatory capacities of M. sexmaculata increased with the increase in prey density. The functional responses of M. sexmaculata adults to the three prey density fitted well with HollingⅡmodel. Chi-square test showed no significant differences between theoretic values and the observed values. There were significant differences in the predatory capacities to the three prey species. The maximum daily predatory capacities of female and male M. sexmaculata adults to B. tabaci, A. craccivora and R. maidis were 86.21, 217.39, 303.03 and 60.98, 151.52, 153.85, respectively. Searching rate of M. sexmaculata decreased with the increase in prey density and was higher on A. craccivora and R. maidis than on B. tabaci. M. sexmaculata adults afforded control efficacy against the three prey species more in A. craccivora, less in R. maidis and still less in B. tabaci, and female adults were more officious than males.