In the present paper, the establishment of biopsychology as well as modern psychology was discussed in terms of physiological findings already known by the 1890s. Source materials were three main biopsychological textbooks in the at 1890s : namely, Grundzuge der Physiologischen Psychologie, 2nd ed.(1880) by Wilhelm Wundt, Elements of Physiological Psychology (1887) by G.T.Ladd, and Principles of Psychology (1890) by William James.