In order to understand the psychological effects of Antarctic isolation and confinement on Japanese expeditioners, psychological studies were done on eight members of a wintering-over party at Asuka Station between December 1990 and February 1992. Mean age of the subjects was 34.8 +/- 5.56 yr. The study includes self assessment questionnaires, psychological tests introduced by the Polar Psychology Project (PPP), a bibliographical study and photographic measurements. There was no pathological depression in midwinter. Subjective and cumulative fatigue symptoms were more noticeable in the older individuals. The Telic Dominance Scale was significantly correlated with the Anxiety Sensitivity Index. The Sense of Coherence Inventory and the Personal View Survey showed an interrating correlation. By analyzing a daily group photograph, seasonal variations in mood and behavior of individuals have been clarified. Consequently, it is hoped that observation of non-verbal signals such as facial expression, clothing, and postures may lead to the development of a new methodological framework for the long-term plan of psychological investigation of the men under severe stress.