The dynamic changes of the main active components in purple potato leaves were studied. The optimal sampling period was determined, and the content of main active components in purple potato leaves, sweet potato leaves and purple potato tuber were compared. The content of total polyphenols, flavonoids and anthocyanins were determined by ultraviolet spectrophotometer, and chlorogenic acid and rutin were determined by HPLC. The results showed that the dynamic characteristics of active components in different varieties of purple sweet potato leaves showed a similar trend, but the content were not exactly consistent in different sampling time, and the content of active components in different varieties were significantly different. The content of active components in purple sweet potato leaves were higher than those in sweet potato leaves and purple potato tuber. The accumulation of several active components in the purple potato leaves was the maximum in the 150 d harvesting period, and the purple sweet potato leaves were abundant. The exploitation and research of purple potato leaves during the harvesting of purple potato tuber are beneficial to the comprehensive utilization of the purple potato resources.