Thyroid cancer is the most common malignancy in endocrine system, and papillary thyroid carcinoma (PTC) accounts for about 80% of thyroid cancer. Papillary thyroid microcarcinoma (PTMC) refers to the PTC with the diameter less than 1.0 cm, with or without lymph nodes metastases or distant metastases. In recent years, with the rapid development and wide application of ultrasonic technology, its detection rate is in a trend of increasing. Generally, PTMC is considered to be in lower malignancy and with good prognosis. However, there are still some reports indicating PTMC have been regional or distant metastasis in lymph nodes when PTMC is diagnosed. In this paper, we reviewed the epidemiological, clinical, biological and molecular biological characteristics of PTMC.