It is an established experimental fact that the yield of urea in urea-synthesis from ammonia and carbon dioxide depends upon the loading density or ratio of the weights of the materials to the total volume of the reaction vessel at a given temperature. The writer showed in the previous paper (2) that the equilibrium pressure as well as the urea-yield is a function of the loading density at a given temperature, and explained that the diversity of the equilibrium pressure is based upon that of the equilibrium composition of the liquid and vapor phase. The object of the present paper is to show the relations within the equilibrium composition of the liquid and vapor phase, the loading density and the temperature, by analysing the composition of the two phases under high temperature and pressure.