Human epidermal growth factor receptor 2 (HER2) protein, is a member of the epidermal growth factor receptors (EGFR or ErbB) family and is a transmembrane tyrosine kinase receptor and, also is high regulated in the ovarian, lung, gastric, oral, and breast cancers. The low specificity and the lack of sensitivity are important restriction in the traditional diagnosis method and other disadvantages such as complex, expensive in FISH, immunohistochemistry and PCR methods led to needing more studies for alternative methods. Biosensor technology has highly effected on the quality of human life through its capacity in sensitivity, specificity, and rapid diagnosis and monitoring of different patient diseases. In this review article, we discuss these biosensors, considering that they have been categorized based on transducer including piezoelectric biosensors, optical sensors such as Fluorescence, Colorimetric and Surface Plasmon resonance, and electrochemical types to the diagnosis of HER-2 and the effectiveness of some drugs against that.