Although a phase transition such as crystallization for food related lipid would play an important role on the stability or various properties of food, there are many unclear issues. Especially, the researches about the phase transition on multi component system including lipid are few. As well as, the knowledge for the phase behavior of their emulsion is limited. In this work, the effect of the composition on the crystallization temperature T_c, i.e. nucleation, and the melting temperatures T_m, for the binary systems, triglyceride binary system and hydrocarbon binary system, was investigated. It was found that both of the crystallization and melting temperature depress logarithmically with the ratio of its composition. Also, there was a linear relationship between the T_c and T_m. These behaviors could be observed not only for the bulky state, but also for the oil-in-water emulsified state. However, it should be noted that, although the T_m for emulsified and bulky lipids gave the same value, the T_c for emulsified lipid exhibited remarkable lower temperature than that for bulky lipid. It is thought that these findings give a kind of quantitative method to understand the physicochemical properties for food related lipid.