The purpose of this article is to introduce the anticancer chemotherapy through the illustration of historical aspects, the different purposes and principles of application, and the concept of dose intensity. Anticancer chemotherapy has been demonstrated in many large-scale clinical trials. Firstly, it is possible to cure cancer by anticancer chemotherapy. Secondly, integrating chemotherapy into combined modality programs with surgery or radiation therapy in early stage of disease can increase clinical benefit. For many years, the oncologists have taken their effort in improving the efficacy of chemotherapy (reduce recurrence and elevate overall survival rate) and, at the same time, lowering the severe adverse effects with varieties of approaches. Currently, the long-term goal of the intense research effort is to improve the clinical outcome for cancer patient's undergoing treatment, especially focusing on cancers that traditionally have been resistant to conventional chemotherapy.