This study investigates the individual characteristics of Japanese polar team members. Four sets of measures from the Polar Psychology Project Battery have been used in Asuka Station. These measures are thought to reflect adjustment and well-being. Data have been collected during 3 consecutive years. The psychological profile of the subjects was relatively stable, and comparable to the standard means of Western sojourners. The results show the subjects were generally high in stress resistance. However, an increase in the Planning Orientation score and a decrease in the Hardiness score appear at the end of the wintering-over. These modifications correspond to psychological changes linked to the approaching end of wintering-over.