Abstract: Lung cancer is the leading cause of cancer-related deaths and has the highest morbidity and mortality among all malignancies worldwide. Non-small cell lung cancer (NSCLC) accounts for more than 80% of all cases of lung cancer. Stage Ⅰ NSCLC (stages ⅠA and ⅠB) accounts for approximately 15%–20% of NSCLC cases. Although surgical resection is the main treatment option for patients with stage Ⅰ NSCLC, the 5-year survival rates of patients with stage ⅠA and ⅠB NSCLC are 83% and 71%, respectively. For patients who cannot tolerate surgery or are unwilling to undergo surgery, radiotherapy may achieve the same therapeutic effect as surgical resection, and there are many new modalities in radiotherapy, such as ablation and particle radiotherapy. This article reviews the specific treatment methods and related prognosis for stage Ⅰ NSCLC.