The experiment was carried out to study the variations and geographical distribution of β -amylase isozyme by isoelectric focusing (IEF) within Korean, Chinese and Japanese soybean land races. In pH 3-10 gel of IEF, the amylase of soybean accessions was separated into low pI group isozymes (TEX>Sp1 b) and high pI group isozymes(Sp1 a). In pH4-6.5 gel, isoelectric points were at 5.07, 5.15, 5.25, 5.40, and 5.94, and h, j, and k bands also were found. The distribution of Sp1 a allele (high pI type) was 29.3% in soybean accessions from Korea, 10.1 % in those from China, and 6.9% in Japanese accessions. The percentage of Sp1 a) allele was the highest in soybean accessions from Kyungsang province (35 %) in Korea, then central China (32 %) in China, and Honshu (10%) in Japan