The study was conducted to assess the effect of species ratio on growth and yield of major carp under polyculture system in perennial ponds for a period of 270 days in haor villages of Sunamganj district. The experiment was designated into three treatments (T1, T2 and T3) based on fish species ratio with three replications each. The fingerlings of Hypophthalmicthys molitrics, Gibelion catla, Labeo rohita, Cirrhinus cirrhosus and Cyprinus carpio were stocked at a ratio of 10, 20, 40, 10, 20; 10, 15, 50, 15, 10, and 20, 10, 30, 20 and 20% in T1, T2 and T3, respectively. Stocked fishes were fed with rice bran and wheat flour at a decreasing rate of 10‒5% of body weight twice daily. Significant (p<0.05) differences in growth and production among treatments were observed. The highest weight gain of H. molitrics (512.89 g), G. catla (432.60 g), L. rohita (439.99 g), C. cirrhosus (346.46 g) and C. carpio (379.60 g) observed in T2. Production of H. molitrics (802.52‒1,477.00 kg ha–1), G. catla (605.25‒1,295.07 kg ha–1), L. rohita (1,880.01‒ 3,731.64 kg ha–1), C. cirrhosus (543.03‒951.42 kg ha–1) and C. carpio (686.66‒ 1,226.38 kg ha–1) varied in different treatments might be due to species ratio. Significantly (p<0.05) higher combined production of carp was obtained in T2 (7,444.98 kg ha–1) followed by T1 (6,625.27 kg ha–1) and T3 (6,007.40 kg ha–1). The highest net profit (BDT 213,695.03 ha–1) was also obtained in T2 than that of T1 (BDT 172,782.89 ha–1) and T3 (BDT 150,440.78 ha–1). Result of the study reveals that polyculture of carp like H. molitrics, G. catla, L. rohita, C. cirrhosus and C. carpio with stocking ratio of 10, 15, 50, 15, 10% in T2 is significantly higher from the viewpoint of growth and production. Therefore, the stocking ratio of 10, 15, 50, 15 and 10% in carp polyculture might be prescribed at farmers’ level in order to boost up fish production, uplift the nutritional status as well as accelerate the economic benefit of the farmers.