Laminarin is a kind of polysaccharide extracted from kelp, which has immunomodulatory, anti-tumor, hypoglycemic, and antioxidation effects. Laminarin extraction from kelp and encapsulation with polymers in supercritical carbon dioxide (ScCO2) are a green and efficient process. The solubilities of laminarin in ScCO2 are one of basic parameters in the process. By using the method of dynamic and static combination, the solubilities of laminarin in ScCO2 with or without the ethanol as a cosolvent were measured under the temperatures of 308.15, 313.15, and 318.15 K and the pressures from 10.0 to 16.0 MPa. The effects of the operating parameters including the pressure, temperature, and content of a cosolvent on the solubility of laminarin in ScCO2 were investigated experimentally. The solubilities obtained from the experiments were correlated by using Chrastil, Mendez-Santiago Teja (M-S T), Del Valle and Aguilera (D-A), Bartle, Thakur-Gupta (T-G), and M-Mendez-Santiago-Teja-Thakur-G (M-MST-TG) models, respectively. The results showed that the calculated values by the models fitted were in good agreement with the experimental ones. The average absolute relative deviations (AARD (%)) without a cosolvent were 4.82, 7.63, 4.73 and 7.91 by Chrastil, M-S T, D-A, and Bartle models, respectively. AARD (%) with the ethanol were 4.45, 6.39, 6.27 and 7.49 by Chrastil, M-S T, T-G, and M-MST-TG model, respectively.