The rice brown planthopper Nilaparvata lugens Stl (Hemiptera: Delphacidae) is an important pest of rice in China. Chemicals application for controlling the planthopper in practice has caused serious problems, such as resistance and resurgence of the pest, and environmental pollution as well. The predacious plant bug Cyrtorhinus lividipennis Reuter (Hemiptera: Miridae) is a common and important natural enemy in paddy fields, feeding on eggs and nymphs of planthoppers、leafhoppers and other insects. In order to evaluate the potential control capability, functional and numerical responses of C. lividipennis (nymph and adult) on N. lugens (egg) were respectively carried out in laboratory. The results showed that the functional response belonged to Holling Type II equation, but nymph of the bug had stronger predation ability than adult when both were feeding on eggs of the planthopper. The strongest predation ability was demonstrated by the 4th instar nymph, with estimated maximum predation as more as 104.2 eggs of the prey in a day. Result of the numerical response test showed that the predator′s growth, development and reproduction were significantly influenced by the prey′s densities. The nymphal developmental rate, female fecundity, hatching rate and female ratio of the predator increased with an increase of the prey′s density, while adult longevity decreased. The minimum prey densities for nymphal survival, adult emergence and population maintenance with low fecundity of C. lividipennis were 1, 3 and 5 egg(s) per day, respectively. It would be concluded from the above results that the plant bug has a potential value to be considered as a biocontrol agent of the brown planthopper. Both functional response and functional response are using as necessary study methods to evaluate the capability of natural enemies, but the functional response emphasis the predation of predator, while numerical response emphasis the dependence of prey density to the natural enemies population, and what impact that will happen to the predator population when prey density changes. As a research method, the combination study of functional response and numerical response can more detailed evaluate the predation of predator and the continuous ability to control pest. That is more meaningful than an unilateral study in the natural enemies use.