Objective: The purpose of this study is to investigate arginase inhibition, antioxidant activity, total phenolic content and total flavonoid content of ethyl acetate extract of Caesalpiniaturtuosa Roxb. Material and method: stem bark of Caesalpiniaturtuosa Roxb was extracted using hexane, ethyl acetate and methanol subsequently. The ethyl acetate extract was fractioned. Then, the fractions were subjected to arginase inhibition, antioxidant activity, total phenolic content and total flavonoid assay. Correlation was considered by statistical analysis. Result: Out of eight fractions, two fractions have no activity. Two fractions (3 and 6) have strong activity in arginase with inhibition 90.72 % and 91.41% respectively. Fraction 3 and 6 have strong antioxidant activity with IC 50 25.98 µg/mL and 48.01 µg/mL respectively. Statistical analysis shows arginase inhibitor activity was not related with antioxidant activity, total phenolic content and total flavonoid content in this plant. Conclusion: Activity in arginase inhibition of fraction from ethyl acetate extract of Caesalpiniaturtuosa Roxb are not related to antioxidant, total phenolic and flavonoid content.