Activity guided isolation of 80% acetone extract from the barks of Acer ginnala Maxim. yielded five gallotannins [6-galloyl-1,5-anhydroglucitol (ginnalin B) (1), acertannin (3,6-digalloyl-1,5-anhydroglucitol) (2), methyl gallate (3), acertannin (2,6-digalloyl-1,5-anhydroglucitol) (4) and gallic acid (5)]. All of these isolated compounds from Acer ginnala(1-5) were firstly isolated from Acer ginnala Maxim. And contents of compounds from barks of Acer ginnala (Comp. 1: 0.73$pm$0.002%, Comp. 2: 0.48$pm$0.001%, Comp. 3: 0.66$pm$0.002%, Comp. 4: 1.05$pm$0.002% and Comp. 5: 0.29$pm$0.001%) were evaluated by HPLC analysis. And, in order to evaluate anti-oxidative activities on Comp. 1-5 isolated from Acer ginnala, DPPH radical scavenging activity was measured in vitro. All of these isolated compounds from Acer ginnala exhibited potent DPPH radical scavenging activities.