Two growth trials were conducted to investigate the effects of DL-carnitine and L-carnitine on the growth, feed utilization and body composition of shrimp Penaeus monodon and Penaeus vannamei. DL-carnitine and L-carnitine were added with different supplement doses (0, 100mg/kg, 200mg/kg, 300mg/kg diet) in the shrimp Penaeus monodon and L-carnitine with different supplement doses (0, 50mg/kg, 100mg/kg, 200mg/kg, 300mg/kg diet) in the diet of shrimp of Penaeus vannamei. Triplicate groups of 40 shrimp (initial body weight of 0.85g) were fed by hand with experimental diets, the growth trial lasted one month. The results showed that the supplementation of L-carnitine or DL-carnitine can not increase the growth rate and improve feed utilization of Penaeus monodon and Penaeus vannamei (P>0.05). In the trial of Penaeus monodon, the lipid content of whole body decreased significantly from 4.69% (control group) to 3.47% and 3.55% respectively with supplementation of 300mg/kg DL-carnitine or L-carnitine (P<0.05). In the experiment of Penaeus vannamei, with the supplementation of 200mg/kg and 300mg/kg of L-carnitine, the lipid contents of whole body were decreased significantly from 7.09% (control group) to 6.04% and 5.72% respectively (P<0.05).