Stage T1 lung cancer refers to the tumor with maximum diameter≤3 cm, surrounded by the pleural membrane of the lung or viscera, and does not exceed the lobar bronchus under the bronchoscope. The prognosis is generally good, but some of them are more invasive, and more aggressive treatments are needed to achieve the best prognosis. This article reviews which T1 lung cancers are susceptible to metastasis and their risk factors. It is hoped that such patients will receive the attention of relevant scholars, and when they are encountered clinically, a more aggressive approach will be taken to extend their life expectancy．