The present study was carried out to study the impact of using some medicinal herbs (0.3gm Garlic / kg LBW/ day ( R2), 0.2 gm Lemongrass / kg LBW/ day ( R3), 0.5 gm Peppermint/ kg LBW/ day ( R4) ,0.2gm Rosemary  / kg LBW/ day  ( R5) versus an supplemented ration ( R1 – control ration which consists of 70% concentrate and 30% hay without any additives  ) on growth performance , some rumen and blood parameters of  twenty five growing Barki lambs. The animals averaged 5 - 6 months old and weighed on average 26 kg.  Animals were randomly divided into five similar groups (five animals each) for 120 days growth trial. The economic efficiency values were calculated. The Results could be summarized as follows: Feeding herbs improved all nutrients digestibility (DM, OM, CP, CF, EE and NFE) and nutritive values as TDN, DCP compared with control ration.Medicinal herbs decreased total lipids and cholesterol .Also, increased total plasma protein and globulin significantly (p < 0.05) compared to the control group. Feed efficiency ( gm gain / gm DM or TDN ) was enhanced in all supplemented groups compared with the control ration. It could be recommended to use 0.3 gm Garlic or 0.2gm Lemongrass or 0.5 gm Peppermint or 0.2gm Rosemary / kg LBW/ day to enhance growth and improve economic efficiency of production and to decrease plasma cholesterol and total lipids in lambs blood