目的：分析Ⅳa期非小细胞肺癌（NSCLC ）的临床特征，探讨其临床诊治的特点及预后因素。方法分析2009年10月至2013年12月收治的首次诊断为Ⅳa期NSCLC患者301例，随访至2014年11月30日，分析其临床特征及诊治情况。主要观察指标为发生率、有效率、无进展生存期（PFS ）和总生存期（OS ）。结果Ⅳ a期NSCLC的患者中位PFS为3．3个月（95％ CI：2．808～3．792），中位OS为7．8个月（95％ CI：6．700～8．900）。多变量Cox回归分析表明，体能状态（PS）评分、胸腔积液是否可控、能否接受4周期及以上化疗是影响疾病进展以及总生存的独立因素，酪氨酸激酶抑制剂（TKI）治疗亦是总生存的独立预后因素。结论Ⅳa期NSCLC中位OS是7．8个月。对于表皮生长因子受体（EGFR）突变患者，应用 TKI治疗；对于体能状态好的患者，积极控制胸腔积液和全身化疗有利于提高Ⅳa期NSCLC患者的生存期。“,”Objective To analyze the clinical features ,characteristics of diagnosis and treatment ,and prognos‐tic factors of stage Ⅳa non‐small cell lung cancer (NSCLC) .Methods 301 patients with initially diagnosed stage Ⅳa NSCLC in our hospital from October 2009 to December 2013 were analyzed on the clinical characteristics ,diagnosis and treatment situation ,including the main observation indicators of occurrence rate ,effective rate ,progression free survival(PFS) and overall survival(OS) .Results The median PFS of stage Ⅳa NSCLC was 3 .3 months (95% CI:2 .808-3 .792) and the median OS was 7 .8 months (95% CI:6 .700-8 .900) .The multivariable Cox regression anal‐ysis showed that the performance status(PS) score ,whether pleural effusion(PE) controllable ,whether accepting 4 weeks or more chemotherapy were the independent factors affecting the disease progress and OS ,the tyrosine kinase inhibitor(TKI) therapy also was an independent prognostic factor of OS .Conclusion The median OS of stage Ⅳa is 7 .8 months .For patients carrying EGFR gene mutation ,using the TKI treatment is beneficial .For patients with good PS ,controlling PE and systemic chemotherapy are beneficial for improving OS .