The genus Garcinia which is rich of secondary metabolites, mainly flavonoids, have known to have antioxidant and anti-inflammatory activity through the inhibition of lipoxygenase. There isn’t found literature indicating research on inhibition of lipoxygenase activity been done in this plant. The purpose of this study is to obtain the data and determine the potential antioxidant activity, and inhibition of lipoxygenase activity of Garcinia porrecta Laness. stem bark extracts. This research is included FRAP (Ferric Reducing Antioxidant Power) method antioxidant assay, in vitro lipoxygenase inhibition assay, flavonoids qualitative analysis by thin layer chromatography, and total flavonoids assay in the most active extract. The results showed the methanol, ethyl acetate and n-hexane extracts of G. porrecta Laness. stem bark using FRAP method, has antioxidant activity with EC₅₀ values ​​respectively 1.33; 4.97; and 19.96 µg/mL and lipoxygenase inhibition activity with IC₅₀ values ​​0.23; 0.52; and 4.87 µg/mL. The most active extract in the both assay is methanol extract which has total flavonoids of 5.66 mg QE/g (quercetin equivalent). The results from the study show extracts of the stem bark of G. porrecta Laness. has antioxidant activity and potention of lipoxygenase inhibition.