In 1963, 16 wild soybeans (Glycine soja Sieb. and Zucc.) and 4 semicultivated soybeans (Glycine max (L . ) Merr.) were collected from localities of different latitude in China (Table 1). They were tested under different photoperiods for their photoperiodic response. The experimental results are shown in Table 2. From the experimental data in Table 2 we can clearly see that wild soybeans collected from Yangtze River Valley (30°18' - 31°54') and south region of China (26°56') are typical short-day plants.