Fish meal and fish oil are considered as the most nutritious and digestible ingredients for marine fish. The prices of both ingredients are higher than the other protein and lipid sources, such as soybean meal and corn gluten meal, and those have made downward trend of usage amount of fish meal and fish oil in aquaculture. The demand of those two ingredients has shown unbalanced conditions for the decades. According to the FAO, the disparity of supply and demand will continue to increase with the continuous worldwide growth of fish and livestock farming (FAO, 2016). Therefore, to lower the price of fish diet and to reduce the content of fish oil and fish meal in aquafeed, it is necessary to find out alternative sustainable dietary ingredients for aquaculture fish species.Plant protein sources were recommended by many authors and their cost seems cheaper and sustainable than fish meal. However, it is well-known that plant protein sources have issue with anti-nutritional factors and are lack of indispensable amino acid. It seems impossible Abstract A feeding experiment was conducted to develop non-fish meal and non-fish oil diet for red seabream by using plant protein source and Schizochytrium meal which is rich in 22:6n-3 (DHA). Three iso-nitrogenous and iso-lipidic experimental diets were prepared (CP 41.2% ± 0.4%, CL 16.4% ± 1%). Control diet contained both fish meal (40%) and fish oil (6%). In the second diet, fish meal was replaced by plant meals (soy protein concentrate, soybean meal, corn gluten meal) [FO]. In the third diet, fish meal and fish oil were replaced by algae meal (Schizochytrium sp. powder) and plant proteins [AO].Duplicated groups of juvenile red seabream (8.8 g ± 1.5) were fed the experimental diets for 12 weeks to near satiation. There was no statistical difference among treatment in specific growth rate. Feed conversion ratio of AO diet group was higher than that of control. In wet basis, whole body protein level was significantly higher in AO diet than FO group while lipid content was lower than control group. In fatty acid profile, AO group had significantly lower level, but significantly higher 18:3n-3 and DHA level than the other two diet fed fish.The results might suggest that further developments in microalgae diet offer a promising lipid source of n-3 PUFA as essential fatty acid on marine fish. And it showed possibility to develop non-fish meal and non-fish oil feed for marine aquaculture fish by using microalgae. K E Y W O R D Salgae, DHA, feed source, fish feed, oil, red sea bream