In this study, the origin and development process of a prevalent Vocational Aptitude Theory of Myeongli in the East were examined in literature. In Old Myeongli, vocational aptitude was mainly determined with Ohsang(五常, five duties), an inborn nature, as its standard, yet in reference to Yuksin(六神, six gods). The decision of vocational aptitude with Ohhaeng(五行, the five elements) and Yuksin as the standards in Old Myeongli can be given the meaning of the beginning of a vocational aptitude Myeongli Theory in that it basically focused on personality applied to today's work theories. In Japyeong Myeongli, Ohhaeng and Ohsang, Gyeokguk(格局) and Yongsin(用神) were considered as important in the discussion of vocational aptitude. When Gyeokguk and Yongsin are applied to the recent vocational aptitude theories, Gyeokguk corresponds to the concept of personality, and Yongsin to that of interest. Ohsang is a person's innate nature and equivalent to personality. Gyeokguk connotes the meaning of the strongest Ohhaeng because the Saenggeuk relationship between Ilgan(日干) as the main agent of Myeong(命) and Wolgan(月支) is usually stressed out. Accordingly, the vocational aptitude theory of Japyeong Myeongli can be said to be the viewpoint focusing on personality rather than on interest. Since the improvement of the quality of life through job satisfaction is more related to what one likes than what one is good at doing, the vocational aptitude theory of Japyeong Myeongli with emphasis on personality rather than on interest seems to have limits. Wei Tianli, a representative scholar of Japyeong Myeongli of the 20th century, categorized jobs with Yongsin Ohhaeng as the standard, and judged vocational aptitude with Yongsin Yuksin as the first priority and the strength and weakness of Gyeokguk and Ilgan as subordinate elements. Wei Tianli's vocational aptitude theory can be highly estimated in that it is a model that has combined personality and interest, yet emphasizes interest, so it takes both personality and interest into consideration.