In this study, we researched the relation between the number of leaves of Heterotropa asper and the environmental characteristics such as the vegetation, the angle of inclination, the cover rate of vegetation, the relative illumination. The relationships between the habit and environmental characteristics in the square section (249 spot) were cleared. As a result, many leaves were detected most frequently under the place where bright on February and dim on May, September. Most leaves were found under trees of Acer rufinerve, which satisfies the light condition mentioned above. Many leaves distributed over the edge of all forest type, including Deutzia crenata was the second place. Moreover, leaves of Heterotropa asper increased on the surface of the earth where plants cover was 30-60%, and distributed along the edge of all forest type. Hence, it is necessary for growth of Heterotropa asper to receive adequately daylight.
