Abstract:To study the application of dietary filamentous alga Enteromorpha prolifera in juvenile turbot , the experiment was conducted to determine the effects of dietary E .prolifera on growth ,feeding and nonspecific immune responses .The turbot juveniles with initial weight (6 .05 ± 0 .03)g were fed five different diets containing green alga E .p roli f era at 0% (E1 ,control group) ,5% (E2) ,10% (E3) ,15%(E4) and 20% (E5) for 42 days .Fish were randomly sampled for analysis of the weight gain rate ,specific grow th rate , feed efficiency rate , food ingestion , macrophage phagocytic activity and macrophage respiratory burst activity .The results showed that the specific growth rate ,growth rate and feed efficiency rate were significantly lower in the E5 group than those in the test group (E1) (P<0 .05) .There was no significant difference in food ingestion among every group (P> 0 .05) .The macrophage proliferation activity and macrophage respiratory burst activity were significantly higher in E 2 group than in the other groups (P<0 .05) .Under the experimental conditions ,there were significantly increase in growth and non‐specific immunity in the turbot fed the diet containing 5% E .prolifera .However ,20% E .prolifera dietary had the negative effects on the grow th and non‐specific immunity in turbot .