The population control of Axinoscymnus cardilobus Pang and Ren (Coleoptera: Coccinellidae) to Bemisia tabaci (Genadius) (Homoptera: Aleyrodidae) on Codiaeum variegatum L. was studied in cages under field condition. The control effects of B. tabaci differed significantly when a pair of adult of A. cardilobus was released against different population densities of B. tabaci. A. cardilobus did not give a satisfactory control to B. tabaci at releasing rate of 1 pair beetle: 20 pairs whitefly. Generally it was very difficult to control B. tabaci population when the beetle and whitefly were released at a ratio of 1:80. Effective control was observed with stable values at range of 35%-95% when A. cardilobus and B. tabaci were released at the ratio of 1:40. Meanwhile, the control effect of B. tabaci was significantly different when different rates of A. cardilobus were released against the same population density of B. tabaci. In case of 1:40, 3:40 and 5:40 ratios, the control effects of B. tabaci were recorded at ranges of 35%-95%, 46%-90% and 50%-98%, respectively. Therefore, the most suitable ratio of predator/prey to consider when control B. tabaci was 3:40 according to the principle of economics and ecology.