The evaluation of the effect of partial replacing protein of sun flower meal (SFM) by protein of azolla meal in concentrate feed mixture (CFM) on growth performance, digestibility, feed intake and conversion and economic feed efficiency of growing lambs it was the aim of the present study. 15male crossbred (Osimi X Flelandi) were divided into 3 equal groups T1, T2 and T3 fed on CFM containing 0, 10 and 20% azolla meal replacing 0,25 and 50%protein of SFM respectively. Results showed that, integrated azolla meal with experimental rations resulted in decreasing the digestibility of DM,OM,CP and NFE and feeding value as TDN and DCP with R2 and R3 rations compared to those of R1 which had highest means (65.61,72.08, 69.69, 77.45,69.81and 8.37,respectively). While, digestion coefficients of CF and EE increased with integrated azolla in rations with highest value in R3.T1 recorded the highest average of final body weight (40 kg) and T3 recorded the lowest average (38.4kg) with insignificant differences among tested groups. Also total body weight gain and average daily gain decreased from T1 up to T3 with insignificant differences among experimental groups. Economic feed efficiency(%) recorded the best value(2.28%) in T2 which had 10% azolla meal followed by T3 which had 20% azolla meal and the lower value (2.15) in T1. The results concluded that dietary insert of azolla meal up to level 10% instead of SFM had positive impact on economic feed efficiency of growing crossbred lambs without any adverse effect on the performance of the animals.