The present study was carried out to estimate digestion, rumen fermentation, milk yield and composition of lactating Barki ewes fed diets with or without different types of algae (Ulva lactuca and Pteroclandia capillacea) at levels of 0, 5 and 10 g/kg diet alone or a combination of both algae, at levels of 2.5 and 5 g/kg diet. Results showed that supplementation of both types of algae at a level of 5 g/kg for each improved (P≤0.05) the digestion of the experimental diets in term of increasing digestibility coefficients of nutrients, especially CP, CF and fiber fractions. On the other hand, digestibility coefficients of the cell wall constitutes were higher (P≤0.05) for diet supplemented with both types of algae at level of 2.5 or 5 g of each. Higher feeding values were obtained for diet supplemented with both algae, followed by those supplemented with each type of algae alone. The highest (P≤0.05) milk yield, milk fat and milk protein were detected by the same diets. Algae supplementation had no effect on milk lactose and ash percentages. It could be recommended to supplement ewe diets with both algae strains (Ulva Lactuca and Pteroclandia Capillacea) at a level of 5 g from each in order to economically improve the performance of lactating ewes.