Leukotrienes are one of the mediators of inflammation which produced from arachidonic acid through the lipoxygenase pathway. The formation of leukotrienes can be prevented through the inhibition of lipoxygenase enzyme activity by chelated iron on lipoxygenase enzyme, so it does not react with the substrate to produce leukotrienes. Anredera cordifolia (Ten.) Steenis leaves have been studied have anti-inflammatory effects at a dose of 50,4 mg/200 g BB with edema inhibition percentage of 10,49%, but the activity in inhibiting the enzyme lipoxygenase has not been studied. The purpose of this study was to test the anti-inflammatory effects of ethanol 96% extract and fractions of Anredera cordifolia (Ten.) Steenis leaves by inhibiting the lipoxygenase enzyme activity measured at λ = 234 nm. Ethanol 96% extract extracted by maceration and 10 times remaceration. Furthermore fractionated by liquid-liquid partition then tested its inhibition of lipoxygenase. The test results showed IC₅₀ values ​​were obtained from the ethanol 96% extract was 0,115 µg/mL. The fraction with the highest inhibitory activity of Anredera cordifolia (Ten.) Steenis leaves is a fraction of ethyl acetate followed by a fraction n-butanol and n-hexane fraction (IC₅₀ 0,197; 2,262 and 7,812 µg/mL). Anredera cordifolia (Ten.) Steenis leaves has high activity for inhibiting the enzyme lipoxygenase if compared to baicalein as a positive control.