Preparation method of a kind of biodegradable gelatinous refrigerant used in temperature control packaging was introduced. NaCl solution was used as main energy storage material and starch based super absorbent polymer as base material of refrigerant. Nucleating agent was added to reduce the degree of supercooling. The results showed the phase change temperature and latent heat of refrigerant decrease while NaCl solution concentration increases; the selected best nucleating agent can reduce the supercooling degree of refrigerant effectively. The research work validated the biodegradable property of the refrigerant and gave the formula and thermal property parameters of refrigerant which is applicable for temperature control packaging under 5 ~ -10 ℃ .