We seek to distinguish human behavior under the persistent temptation. In particular, we want to study on the willpower depletion by manipulating the different frequency of temptation. We conducted a laboratory experiment to try to answer this question. The main result shows that the higher frequency of temptation does make subjects work shorter, which supports the story of limited willpower. Moreover, this result might also be able to give people a suggestion on reward scheme to help them maintain their willpower. It could be applied on managing human capital and maintaining self-control.