A confined field experiment was conducted to investigate biological control of malaria and inland filariasis vector, Anopheles sinensis Wied. by combined use of larvivorous fishes, Aplocheilus latipes or Aphyocypris chinensis and herbivorous, Tilapia mossambicus niloticus in natural rice fields at Banwol near Suwon, Gyeonggi province from June through October, 1989. In the presence of naturally breeding Aplocheilus at the density of 0.8 fish/$m^2$ water surface, the natural control of Anopheles larvae ranged 34.4% to 51.6% from June through August; later supplemental introduction of herbivore (Tilapia) at the release rate of I-pair per $10m^2$ resulted in 67.8% increased to 80.0% control of Anopheles sinensis in 3rd and 5th week respectively. In a combined fish release at the rate of 1.0 fish/$m^2$ of Aphyocypris and 1-pair/$l0m^2$ of Tilapia produced 67.3% and 82.1 % mosquito larval reduction in 3rd and 5th week periods, respectively. The similar pattern of gradual but significant suppression of mosquitoes was also evident in separate rice paddy in 4-5 week period, maintaining ca. 75-82% for the subsequent mosquito breeding season in comparison with control plot.