Wild soybean plants(Glycine ussuriensis) collected from Korea(47 strains) and abroad(41 strains) were grown under field condition and classified according to the growth habit. Seeds were analyzed for protein content. The results were as follows: 1. Wild soybean plants were classified into three groups each by seed size, growth habit of stem, leaf size and flowering time. 2. Seed protein was higher in the strains with large leaves, tendril, stem or late flowering. 3. Glycine gracilis, supposed to be the intermediate species between cultivated and wild soybean(according to the stem growth habit, straight or semitendril, and seed size) was medium in protein content of seeds. 4. The average protein content of Glycine ussuriensis, 43.2%, was highest in comparison with those of others such as G. gracilis, 37.5%, or G. max, 36.2%. 5. One hundred seed weight of Amphicarpaea trisperm, similar to the wild soybean, was almost same as Glycine ussuriensis, but protein content of this species was lower than wild soybeans.