〔Abstract〕 Objective To investigate the prevalence of sarcopenia in patients with lung cancer, and to explore the influencing factor in lung cancer patients with sarcopenia. Methods A total of 78 lung cancer patients(lung cancer group) and 78 healthy subjects(control group) were selected. The body measurement of the two groups were measured by bioelectrical impedance method. Height-adjusted appendicular skeletal muscle mass index(ASMI) was used to define sarcopenia. Results The prevalence of sarcopenia in lung cancer patients was higher than that in controls(61.5%vs17.9%, χ2=30.943,P<0.001). Compared with the control group, the protein, fat free mass(FFM), soft lean mass(SLM), appendicular skeletal muscle mass(ASM) and ASMI levels of the lung cancer group decreased(allP<0.05), while the visceral fat area(VFA) of lung cancer group increased(P<0.001). The weight, body mass index(BMI), protein, FFM, SLM, ASM, ASMI and body fat mass(BFM) of lung cancer patients with sarcopenia were lower than those of lung cancer patients without sarcopenia(allP<0.05). There was a difference in the incidence of sarcopenia between different BMI groups in the lung cancer patients(100%vs62.5%vs33.3%, χ2=13.569,P=0.001). Pearson correlation analysis showed that ASMI was positively correlated with height, weight, BMI, protein, FFM, SLM and ASM(allP<0.001), while it was negatively correlated with age and percent body fat(PBF)(allP<0.05). Binary Logistic analysis showed that higher BMI(OR=-1.997, 95%CI: 0.046-0.400,P<0.001) and higher ASM(OR=-2.696, 95%CI: 0.012-0.389,P=0.003) were the independent protective factors for the lung cancer patients with sarcopenia. Conclusion Lung cancer patients have higher prevalence of sarcopenia. Higher BMI and higher ASM are the protective factors for the incidence of sarcopenia in patients with lung cancer.