Analysis of black soybeans [Glycine max (L.) Merr.; 59 Korean varieties] revealed that 100-seed weights of green cotyledon seeds (33.5 g, n=31) were higher than those of yellow ones (28.9 g, n=28). Contents of delphinidin-3-glucoside (D3G), cyanidin-3-glucoside (C3G), petunidin-3-glucoside (P3G), and total anthocyanins in seed coats of black soybeans were 0.03-4.15, 0.74-18.36, 0.02-1.60, and 0.87-23.52 mg/g, respectively, among which most prominent anthocyanin was C3G (80.9% of total content), followed by D3G (13.6%) and P3G (5.5%). No significant differences were observed in color parameters $a^*$ and $b^*$ between black soybeans with yellow cotyledon (BYC) and green cotyledon (BGC). Total isoflavone content of BGC was higher than that of BYC, and negative correlation was found between total anthocyanin and isoflavone contents.