Abstract: In recent years, Ganzeboom and Treiman constructed the new Standard International Prestige Scale and Occupational International Socio-Economic Index (ISEI) of Occupational Status which was adopted by more and more researchers in Taiwan. In this study, the author used random sampling to select respondents from samples of higher education survey and digital divide survey. Besides, the author used close-ended and open-ended questionnaires to survey the occupations of students’ fathers. The purpose of this study is to assess the quality of three occupation measurements: based on the score of the ISEI and the “New Taiwan Occupational Socio-Economic Scale (NTSEI)” which is transformed from the occupations of respondents’ fathers in open-ended questionnaires, and the five-rank social economic status measure which is transformed from the major group occupations of respondents’ fathers in close-ended questionnaires, which is indigenous, easy to measure and low cost. The findings are as follows: five-rank measure has the lowest missing value percentage, while NTSEI in the middle, ISEI the highest. As to the construct validity: NTSEI is highest, five-rank measure in middle, however, ISEI reveals serious problems.