Although many anticancer therapies are used in clinic, few are tolerable for their side effects from killing of normal cells. Seeking measures to target anticancer agents to tumors or at least tumor-located organs has been one of the major tasks for researchers. Nanotechnology is greatly helpful for fulfilling this task. There are several ways to direct therapeutic agents carried by nanoparticles to tumor sites. This article focuses on the mechanisms,advantages and disadvantages of different targeting manners, understanding of which may be benefitial to researchers to develop specific targeted anticancer therapy.