The purpose of this study was to explore, if any, some fundamental theories and/or philosophies which were considered as the bases of the Reality Family Therapy. Four theories and/or philosophies were found. They were existential philosophy, system theory, social constructivism, and positive psychology. Inference was made based upon the results that the Reality Family Therapy could be a very powerful approach in the areas of individual and group, and family counseling as well within brief period of time.