Abstract: Breast cancer is the second leading cause of cancer death in women. The diversity of its classification is closely related to clinical treatment. In recent years， with the rapid development of molecular biology， great progress has achieved in breast cancer treatment，but drug resistance is still the most common problem in first-line clinical treatment. In this paper，we study on the different types of breast cancer and their characteristics，as well as discussing different treatment options and drug resistance mechanism.We hope that we can provide guidance for clinical treatment of breast cancer.