Grass carp fishes were caught approximately in the same size (initial weight: 10 grams) from earthen ponds and maintained in the laboratory in 15 glass aquaria (35 cm x 70 cm x 40 cm) containing 98L of filtered Nile water in 5 treatments (3 replicates per treatment) control, T1, T2, T3, T4 with stocking densities (10 fish/aquarium). The fish diet provided was a commercial floating pellets diet containing (30% protein, 6% lipids, fibers 4.5%, total energy not less than 4100-kilo calories / Kg ) and Azolla plant which was cultivated. Fish fed at 5% of their body weight in the control group and replaced with Azolla plant in the T1, T2, T3, T4 with percentages 25,50,75,100 % respectively. The current study showed that replacing the artificial feed with Azolla pinnata positively enhanced the growth performance, haemato-biochemical values, of grass carp. These results indicated that Azolla pinnata with a rate of 25-50% can be considered a beneficial dietary supplement for grass carp.