Each year, approximately two million new HIV infections are reported worldwide. About one decade ago, a company called Gilead Sciences Inc. discovered a new HIV prevention method named as pre-exposure prophylaxis (PrEP). When high adherence was kept among high-risk population, PrEP efficacy could reach as high as 99%. However, the adverse effects have been reported from time to time, including low efficacy in certain cases, adherence difficulties and medicinal side effects. In this review, we would summarize the progress of PrEP since its introduction in order to provide insights for HIV prevention.