Solanum erianthum is one of the herbal plants that is believed by the Indonesian people to be a medicinal plant. The flavonoid and polyphenol compounds contained therein have antioxidant activity, but this has not been proven empirically. Solanum erianthum extract is produced using the maceration method. The determination of total flavonoid levels in Solanum erianthum was measured using a method based on complex formation, namely the aluminum trichloride (AlCl3) method. The antioxidant activity of Solanum erianthum was measured using the DPPH (1,1-diphenyl-2-2picrihydrazyl) method because of its stability in the form of free radicals and because it is simple to carry out. The results obtained after determining the total flavonoid content in Solanum erianthum extract with various concentrations using the aluminum trioxide method were 1,430 mg QE/g, 2,282 mg QE/g, 3,180 mg QE/g, 3,567 mg QE/g, 4,291 mg QE/g. Solanum erianthum extract demonstrated antioxidant activity in the DPPH test, with an IC50 value of 66.493 g/ml. This falls into the “strong” category. This research shows that the phytochemical screening content of Solanum erianthum extract contains alkaloids, flavonoids, tannins, saponins, and tritepenoids. The total flavonoid content in Solanum erianthum extract at concentrations of 6 µg/ml, 8 µg/ml, 10 µg/ml, 12 µg/ml, and 14 µg/ml is as follows: 1,430mg QE/g, 2,282mg QE/g, 3,180mg QE/g, 3,567mg QE/g, and 4,291mg QE/g, as well as the antioxidant activity of Solanum erianthum extract with an average yield of 69,493 ppm.