Motivation research in sport psychology has focused largely on personal motivational factors such as values, expectations and needs. In recent years, however, studies that consider significant others (coach, parents, and peers) as environmental motivational factors are drawing attention. The motivational climate that applies the achievement goal theory proposed by Ames (1992) is a framework that structures the relationship between the athletes and his/her significant others from the viewpoint of motivation. Numerous studies have been conducted since Seifriz et al.ʼs (1992) development of the Perceived Motivational Climate in Sport Questionnaire (PMCSQ). In approximately 20 years, motivational climate research has become widespread not only in Western countries but also throughout the world, which underscores the meaningfulness of motivational climate research findings. Indeed, only motivational climate research can reveal the behaviors of significant others that render the athleteʼs motivation adaptive or maladaptive. In contrast to such vigorous research trends overseas, studies in this area are still developing in Japan. Therefore, this paper will address issues in the motivational climate research conducted in Japan while reviewing the research trends overseas. This paper consists of the theoretical framework of motivational climate, trends in motivational climate research, issues with motivational climate research, and prospects for the future.