Thyroid carcinoma is one of the most common diseases in the head and neck area. With the advance of innovative technologies like ultrasound ,fine-needle aspiration and PET-CT, the number of patients diagnosed as thyroid carcinoma has grow rapidly during the past ten years. As a special structure in papillary tumors and appearing as microcalcification in the imaging examination, psammoma body has been considered of great significance in the diagnosis of thyroid carcinoma. Psammoma body has unique features in terms of pathology, cytology and imageology.The study of the mechanism of psammoma body formation is very important for the clinic to differentiate the disease from others. In this article, we summarized the role of psammoma body in the study of thyroid cancer.