Integrated culture of Litopenaeus vannamei postlarvae with different densities of Gracilaria corticata was examined during a 30-day period from July 17 to August 16,  2018. Four  treatments of nursing the whiteleg  shrimp L. vannamei  post larvae (PL₁₅) at a density of 2000 Pl/m² integrated with  different densities of red sea weed (0, 400 , 800  and 1200 g algae/m²) (T₁,T₂, T₃ and T₄) plus a control treatment, culturing of red algae Gracilaria corticata at a density of 400 g without shrimp (T₅) were compared. Based on the results, the survival rate, the specific growth rate(SGR) and the final weight  of L. vannamei  (95.33±3.05, 12.26±0.02 and 543.7±47.88) in  treatment T₄  were significantly higher than the treatments T1 and T2 (p<0.05). The maximum SGR of G. corticata  (2.37±0.88) and the highest percentage of weight gain (WG) (103.5 ± 5.02%) was observed in treatment T₂. The minimun SGR  (0.23±0.10) and the minimum WG (7.08±3.15%) was observed in treatment T₅. This research clearly showed that culturing of red algae G.corticata  in the nursery tanks of  L. vannamei  post larvae could lead to increase the growth parameters and survival rate of post larvae and the increasing in these parameters were significantly related to the density of algae in tanks.