Abstract:This article discuses the microwave-assisted extraction of anthocyanin from purple sweet potato and the way to quantitatively detect anthocyanin under visible spectrophotometer measure system. The result demonstrates that the determination of absrbance of anthocyanins in the sample at the 520 nm，the relative standard deviation is 5.26 %（n=6），average recovery at the spiked level is 97.8 %，the minimum detectable concentration of anthocyanin is 0.835 μg/mL. The present invention provides a quick easy way to quantitatively detect anthocyanin in purple sweet potatoes.