Changes in protein, amino acids composition and protein activity of native Meju were investigated at various time intervals over 6 weeks of fermentation by using, gel filtration, and amino acid analyzer. From the quantitative fractionation of native Meju proteins, albumin content (36.4%) was the highest at 4 weeks. During Meju fermentation, albumin increased gradually but glutelin decreased up to 4 weeks. Globulin and prolamin content did not change substantiantiall. When albumin was fractionated by Sephadex G-200, two main peaks were fractionated and a new peak appeared after 4 weeks. Its molecular weight was extimated to be 66,000 by the gel filtration method. Amino acid composition of albumin in native Meju appeared to be 17 kinds. Glutamic acid content (87.98-317.10) were the highest, followed by aspartic acid and glycine. The proleolytic enzyme activity increased when the native Meju was fermented and marked the maximum value at 4 week.