This work was carried out on male Barki lambs to investigate the effect of substitution of berseem hay (Egyptian clover) with Prosopis  Juliflora and Kochia,  on growth performance and some blood constituents as well as economic efficiency. Twenty growing Barki males at 4-5 months with an average live body weight (LBW) (24.26 kg) selected from a herd of Borg El-Arab Station- Alexandria- Egypt APRI- ARC. The lambs.were randomly divided into 4 similar groups (5 animals each). The 1^st group (Hay) was fed the control diet which consisted of 40% concentrate feed mixture plus 30% berseem hay (BH) plus 30% treated rice straw, while in the 2nd,3rd and 4th groups, Brseem Hay as percentage was replaced by Prosopis  Juliflora, Kochia and mixture of Prosopis  Juliflorar and Kochia respectively. Condensed tannins (CT) were determined according to the description of Harinder et al., (1993). Blood samples was analysis. Commercial kits were used for all biochemical determination. Data was statistically analyzed by the GLM procedure of SAS (2003). The data indicated that the highest value of DM intake (971 g/h or 59.13 g/kgw0.75) was recorded with T1. However, the crud protein intake as g/d or g/kgw0.75 for growing lambs was not affected by the tested rations. During the whole period (14 weeks), Daily body gain was improved with T2 and T4 by 16.28 and 23.75%, respectively compared with T1. But, the obtained results detect slight differences between T1 and T3 without significance. The effect of replacing berseem hay with Prose in Juliflora alone or Kochia on total protein and urea-N without affecting liver function was significant with T2 and T4. Replacing BE with greenery, on the other hand, resulted in a lower feed coast and increased economic efficiency (T3, T4, and T2, respectively) compared with T1. In conclusion:  feeding on Prosopis  Juliflora or Kochia  and mixing Prosopis  Juliflora with Kochia, instead of clover hay may improve growth performance and some blood constituents of  Barki Lambs.