This study has investigated the one year adaptation process of female cadets and male cadets after their entrance. The subjects of the study are 182 male cadets and 19 female cadets at the Korea Air Force Academy. The measure of the adaptation process is completed by quantitative methods using Cadets Adjustement to Academy, Korean Symtom Checklist and their GPA. The theme of the adaptation process is analysed by small group interviews. The results of the study are as follows. First, adaptation pattern of the first grade is 'V' which means that the level of the adaptation is the lowest at the end of the first semester. Second, female cadets have more problems than male cadets in adaptation and mental health. Third, female cadets are higher than male cadets in academic achievement scores but in military conduct scores, the result is reversed. Fourth, the trends of the adaptation process are from external to internal, from individual to group and from assimilation to accomodation. All these results are discussed in the context of the physical and psychological environment of the academy.