The purpose of this study is to develop the cold chain system by developing optimal phase change materials (PCM). There are some benefits from developing this system such as keeping freshness of agriculture products, saving energy, etc. The major results are as follows. To decide a latent heat material, the characteristics of water, sodium, polyacrylate, ethanol and N-tetradecane are analysed. Also, an insulating material is made by mixing water, nucleating agent and latent heat material, using cementing method. In addition, the sensitivity analysis for developed latent heat material($K_l,;K_2,;K_3$) is conducted. For $K_l,;K_2,;K_3$ which cans keep latent heat temperature, ranging from $0;to;5^{circ}C,;5;to;10^{circ}C,;10;to;15^{circ}C$. it can keeps latent heat temperature at radiant heat (5, 12, $17^{circ}C$) and transportation latent heat container both melting temperature and amount of latent heat of Kl are $-1.6{pm}1.0^{circ}C$, 326.51 J/g, respectively and freezing temperature and latent heat are $-7.98{pm}1.5^{circ}C$ and 174.18 J/g. and $K_2$ are $7.41{pm}1.5^{circ}C$, 89.80 J/g, respectively and freezing temperature and latent heat are $-2.14{pm}1.5^{circ}C$ and 83.90 J/g. and $K_3$ are $9.54{pm}1.0^{circ}C$, 145.42 J/g, respectively and freezing temperature and latent heat are $0.21{pm}1.0^{circ}C$ and 152.48 J/g.