Effect of feeding on different algae to brackish water rotifer (Brachionus plicatilis) was implemented to access their population growth. The first experiment was carried out to find out the suitable algae for rotifer feeding with 5 appropriate algal species: Chlorella sp.; Nannochloropsis oculata, Isochrysis galbana, Chaetoceros calcitrans and Tetraselmis suecica and three replicates for each treatment. The initial density of rotifers was 200 ind./mL. Feeding of rotifers with algae was 60,000 cells/ind./day and water exchange up to 30% per day. Results indicated that the maximal population density for B. plicatilis in feeding of T. suecica treatment was 6, 278±706 ind./mL on the 6^th cultured day The second experiment had been evaluated the effect of concentrations of the best algal food (T. suecica) with 3 treatments and three replicates: 50,000; 60,000 and 70,000 cells/ind./day. Cultured conditions in this experiment had been the same in the first one.  The concentrated of T. suecica of 70,000 cells/ind./day of feeding had the highest density of rotifer (8644±241 ind./mL) on the fifth day of cultured period.