The study was conducted to determine the content of phenolics and flavonoids, antioxidant activity and antioxidant enzyme activity for the extract from 7 days old sprouts of cowpea (cv. "Seowon"), mungbean (cv. "Owool") and soybean (cv. "Pungsannamulkong"). Sprout length and weight of soybean sprouts were higher than those of cowpea and mungbean sprouts. Total phenolics content [mg ferulic acid equivalents (FAE) $kg^{-1}$ DW] was highest in soybean sprout extracts (82.2 mg $kg^{-1}$), followed by cowpea (32.2 mg $kg^{-1}$) and mungbean (24.5 mg $kg^{-1}$) sprout extracts (p < 0.05). The result of total flavonoid level [mg rutin equivalents $kg^{-1}$ DW] had same tendency to the total phenolics, showing lower amounts. The antioxidant activity of the methanol extracts from all the plant dose-dependently increased. DPPH (1,1-diphenyl-2-picryl hydrazyl radical) free radical scavenging activity was higher in cowpea (44%) and mungbean (42%) sprouts than in soybean sprouts (25%). Among antioxidant enzymes, APX and POX activities were highest in cowpea sprouts and CAT and SOD activities in soybean sprouts. The results showed that total phenolics content ($r^2$ = 0.5320 ~ 0.9032) and total flavonoids level ($r^2$ = 0.4672 ~ 0.9380) were highly correlated with antioxidant or with antioxidant enzyme activity, and that the level and activity of biologically active substances were different depending on plant species.