Purple sweet potato has the potential as a natural antioxidant based on the high levels of anthocyanin contained therein. Anthocyanin is polar compounds that are more easily extracted in acidic conditions. Antosianin has benefits as an antioxidant and antidote to free radicals, so it plays a role in preventing the occurrence of aging, cancer, and degenerative diseases and others. The purpose of this study was to determine the appropriate solvent and pH to extract the purple sweet potato anthocyanin by the method of differential pH spectrophotometry. Samples were added 96% ethanol and the aquades were acidified with 1% HCl so the pH of the solvent was 1, 1.5, 2, and 2.5. The extracts obtained were diluted with pH 1 and pH 4.5 solvents and then determined their anthocyanin levels based on the spectrophotometric differential pH method. The results showed that solvent and pH had an effect on total anthocyanin content. The ethanol and pH 1,5 solvents gave the highest total anthocyanin content and the highest purple sweet potato absorbance of 5.9558 mg / L.