There is no national standard yet for measuring anthocyanins of purple tea leaves. The methods for determining Anthocyanins of tea leaves by single-pH and pH-Differential spectrophotometry were compared in this paper. The results indicated that anthocyanins content measured by single-pH was much more than that measured by pH-Differential spectrophotometry. The two methods had good linear relation (R2=09927). The effects of interfering substances on quantitative analysis of anthocyanins could be eliminated by using pH-Differential spectrophotometry. The results provided a reliable basis for the measurement of anthocyanins.