The study attempts to estimate and evaluate the rates of return on graduate degree holders who major in science and engineering. The model of this study adopts the rate of return method considering unemployment as well as mortality rate. The data are collected by questionnaires and interviews. The results show that the social rate of return(SROR) of bachelors is lower than the rate of return on investment in physical capital which is assumed as a decision criterion of public investment in Korea, but the SROR of Ph.D. holders is balanced. The results also show that the private rates of return (PROR) of all the levels in postgraduate science and engineering education are higher than the private discount rate which is a decision criterion of private investment in Korea. It also indicates that the PROR on investment in graduate education is not likely higher than the SROR because an individual bears high share of the educational costs.