Fish meal is one of the most expensive ingredients in prepared fish diets. Therefore, we used of unconventional feed such as algae for substitution the high cost feedstuff such fishmeal with support the maximum growth of fish. In addition to the highly content of protein and essential fatty acids of algae, and more suitable for fish diets, algae production rates where high in tropical and subtropical developing countries. A 12-week feeding trail following by a 2-week digestibility trail were conducted with Nile tilapia fingerling , a control diets without micro algae served as a reference from which inclusion levels of 5, 10, 15 and 20% micro algae were investigated by the replacement of fish meal. Generally, it could be noticed that the inclusion of algae levels up to 15% for Nile tilapia fingerlings produced optimum growth performance, feed utilization and efficiency and digestibility coefficient. Also 10 or 15% algae in the diet improved physiological status and reproductive in items of FSH hormones for Nile tilapia. The present study should help shed some light on this micro algae new source for protein in fish diet which highly elements content and improve fish performance.