Abstract:Fed with feeds containing seven levels of Spirulinaplatensis (0, 0.2%, 0.5%, 0.8%, 1.5%, 3%, 5%) for 8 weeks respectively, the grouped Litopertaeus vannamei were weighed and counted on the 28th and on the 56th day. And the body composition (crude protein, amino acid, fatty acid, etc. ) and hepatopancreas somatic index (HSI) were investigated at the end of the experiment. When the dietary level of Spirulina platensis was 0.8% and 1.5%, the shrimps had more rapid weight gain (WG) with the 28th WG 926.10% ,959.78% respectively and the 56th 4382% ,4353.3%. And when the dietary level of Spirulina platensis was 0.8%, the feed conversion ratio (PCR) was 1.32, the lowest; and protein efficiency ratio(PER) was 1.296, the highest. The EPA content of the shrimp body(Y) had good linear relationship with the S. platensis supplementing level(X) within the 1% addition level ( YEPA = 2. 4275X + 4. 5975, R^2 = 0. 9611 ), at the same time, the DHA and ARA content had remarkable linear relationship with the S. platensis within the level of 0.8% ( YDHA = 4. 668X + 5. 6545, R^2 = 0. 9631 ; YARA = 105.58X + 0. 3241, R2 = 0. 9749). The HSI of the shrimp had the decrease tendency along with the increase of the dietary level of S. platensis. These results showed that the S. platensis had some beneficial grow performance and the digestive/absorbent rate, especially when the addition level was 0.8 %. The S. platensis had remarkable effect on the deposition of high unsaturated fatty acids(HUFAs). According to the equation of dietary level of S. platensis and HUFAs, when the level was 3.67 %, the total contents of HUFAs of shrimps peaked.