Abstract: Sodium acetate trihydrate(CH₃COONa·3H₂O)has been focused as a phase change material because of its large latent heat of fusion which makes it attractive as a latent heat storage material.Its melting temperature makes it suitable for applications in such as solar energy storage for domestic hot water.However,two main problems with CH₃COONa·3H₂O are supercooling and phase segregation.Through study and comparing the energy storage property of CH₃COONa·3H₂O with different additives of nucleating agents and thickeners under continuously melting and thawing,it is found that carboxy methyl cellulose is better than gelatin as a thickener for CH₃COONa·3H₂O,while Na₂SiO₃·9H₂O and Na₂B₄O₇·10H₂O as nucleating agents for CH₃COONa·3H₂O is good.