Background: Flavonoids, polyphenolic compounds that are ubiquitous in nature, have been known for their pharmacological as antifungal, diuretic, antihistamin, antihypertension, insecticide, bactericide, antiviral, antioxidant, and enzim inhibitor. Flavanones found in all parts Scutellaria indica, has the ability to inhibit arginase, flavanols found in the seeds of Theobroma cacao L. Previous study showed that Caesalpinia ferrea C. Mart stem bark contains flavonoid compound. Objective: The objective of this study to analyze arginase inhibitory activity and to determine the total flavonoid content of Caesalpinia ferrea C. Mart stem bark by using AlCl3 colorimetric method. Methods: Dried Caesalpinia ferrea stem barks were refluxed with three different solvent with gradual gradient polarity i.en-hexane, ethyl acetate, and methanol. Each extract was tested to determine arginase inhibitory activity. Total flavonoid content was determined on extract showed the highest arginase inhibitory activity. Results: Methanolic extract showed arginase inhibitory activity of 12.81% and flavonoid content was 2 mgQE/g. Phytochemical screening on Caesalpinia ferrea stem bark ethyl acetate extract showed that it contains flavonoids, tannins, saponins, steroids, and terpenoids, meanwhile Caesalpinia ferrea stem bark methanolic extract contains flavonoids, tannins, saponins, and steroids. Conclusion: Caesalpinia ferrea C. Mart stem bark extracts were not potential to inhibit arginase.