Purple sweet potato (Ipomoea batatas cultivar Ayamurasaki) is one of the most abundant tropical food crops in Indonesia. Purple sweet potato has a very feasible potential to be considered in supporting a food diversification program based on flour products. The purpose of this study was to determine the nutritional composition and content of bioactive compounds in cakes made from processed purple sweet potatoes without and with fermentation. The cake microstructure was observed and documented using a SEM (Scanning Electro Microscopy) microscope. Organoleptic preference test was done in hedonic form (like or dislike) on taste, aroma, texture and color. Data were analyzed using SPSS software with ANOVA analysis. The nutritional results of the fermented purple sweet potato cake increased in the content of carbohydrates, fat, ash, dietary fiber, amylose, amylopectin while the protein and water content decreased. The result of the content of bioactive compounds from purple sweet potato cake with fermentation was an increase in the content of antioxidants, flavonoids while the content of polyphenols decreased. SEM results from purple sweet potato cake crumbs without and with different fermentation. The hedonic test results in terms of taste, aroma, and texture of cakes with flour without fermentation are preferred, while in terms of color without and with fermentation cakes are equally preferred.