In this study, the commercial seaweeds were cultivated in the Persian Gulf coastal areas. A culture system for two agarophyte and carrageenophyte seaweeds Gracilariopsis persica and Hypnea flagelliformis has been developed, using floating rope for grow-out. Correlations between RGR and environmental parameters were investigated using Pearson correlate Test. The results indicated that the highest biomass for Gp. persica (RGR = 28.77 ± 0.4% day-1) and H. flagelliformis (RGR = 25.16 ± 0.3% day-1) was obtained in February and January, respectively. In seaweed Gp. persica, positive correlation was found between RGR and O2 (r = 0.558; P< 0.001), and negative correlations were found between RGR and temperature (r = -0.657; P< 0.001) and salinity (r = -0.607; P< 0.001). In seaweed H. flagelliformis, negative correlation was found between RGR and temperature (r = -0.706; P< 0.001). These results demonstrated the great potential of Gp. persica and H. flagelliformis for  mariculture.