There are many problems facing the marine aquaculture in Egypt.This is due to the lack of availability of information on the care of these conditions inside the fish hatchery, which achieve higher growth rates and survival. So targeting the current study, which was conducted in NIOF Marine Hatchery, National Institute of Oceanography and Fisheries, El-Max Research Station, Alexandria. The present study  aims at evaluate the stocking  densities (12 fry/aquaria & 25 fry / aquaria) and add moss (Chlorella or Nannochloropsis) on some growth performance and benefit from food and condition factor and chemical composition of sea bass of fry has been included each transaction on the duplicates and the average weight of sea bass D. labrax fry(0.48 g / fry) in the beginning where they were fed on diet containing 57% protein, with a daily average of 5% of the total live weight of the fish. The results indicated that at lower stocking density (12 fry / aquaria) in the Empty water from algae showed significantly (p≤ 0.05) better growth performanceand feed efficiency compared with water genitive algae. It may be concluded that the addition of both green water Chlorella and moss Nannochloropsis has no Influence on the performance of the fry of sea bass (Dicentrarchus labrax L.) during the post-weaning period.