The purpose of this study was to analyze the composition and abundance dominant plankton and macrobenthos organisms in Litopenaeus vannamei rearing ponds, Delvar, Busher, Iran, and their importance in daily food intake during 113 day period. Samplings were conducted after stocking the ponds with postlarvae (PL 12 ) every 15 days, starting from (July 2009). Samplings were carried out for phytoplankton by water collection, for zooplankton by zooplankton net (55 µm mesh size), and macrobenthos by grab (25×25 cm dimension). During culture period, the water and shrimp post larvae/ larvae were sampled. Results showed that ponds water had 45-50 g/L of salinity, 3.5-5.5 mg/L of dissolved oxygen, 8.1-8.4 of pH and 24-32 ?C of water temperature. The phytoplankton community were Bacillariophyceae, Dinoflagellates, Cyanobacteria and Chlorophytes, with Navicula, Coscinodiscus and Nitzschia being dominant. The main groups of zooplankton during each sampling period consisted of rotifer, copepod and meroplanktonic organisms. The copepod assemblage belonged to Calanoidae, Cyclopoidae and Harpacticoidae with mean abundance were estimated to be 3-17, 0.2-5.0 and 0-1 individuals/L, respectively. The major copepod species were Acartia , Centropage and Oithona during L . vannamei rearing period. On the other hand, the rotifer, Brachionus plicatilis, was dominant at the beginning of culture and its abundance varied between 0 to 122 ind./L. The meroplankton community during culturing period were consisted of Trochophore, Scyphomedusae and Phyllosoma larvae. Macrobenthos: polychaeta and chironomid were dominant among macrobenthic community, with relative abundance of 16.7% and 83.3%, respectively, and total absolute abundance of 0-352 ind./m 2 . Correlation analyses showed were no significant correlation (P 0.05) between pH and dissolved oxygen and zooplankton abundance, while there correlative (P 0.05) between water quality parameter and macrobenthos abundance. Results stated that specific growth rate of L. vannamei in rearing ponds varied during culturing period, and its mean was 3.03 mg/day and 0.93 mm/day. The gut contents of L . vannamei were mainly included artificial shrimp food, phytoplankton, zooplankton and macrobenthos which indicated this species consumed different food sources either in pond or in artificial form. Further study on gut analyses were conducted using gut fullness and color index. The highest gut fullness was obsorved in foregut (0.95%) and the lowest in hindgut (0.20%), while colore index were dominant with brown- Key words Litopenaeus vannamei , Zooplankton, Macrobenthos, Phytoplankton, Specific Growth Rate, Gut Contents, Gut Fullness, Color index.