Abstract: Objective To investigate the correlation between CRP/Alb ratio（CAR）and the clinicopathological features of small cell lung cancer（SCLC）patients and its prognostic value. Methods A total of 80 SCLC patients who were initially treated in the Affiliated Hospital of Xuzhou Medical University were enrolled as a treatment group and their CRP and Alb before treatment were retrospectively analyzed.Meanwhile,another 80 healthy subjects were selected as a control group.The CRP/Alb ratio（CAR）was calculated.The correlations between CAR value and the clinicopathological characteristics and prognosis of SCLC patients were analyzed. Results The treatment group produced remarkable higher levels of serum CRP（6.95 ± 3.21）mg/L than the control group（3.13 ±1.69）mg/L（P＜0.05）; marked lower levels of Alb（35.71 ± 6.68）g/L than the control group（45.63 ± 5.78）g/L（P＜0.05）and significantly higher levels of CAR（0.20 ±0.10）than the control group（0.07 ± 0.04）（P＜0.05）. Survival analysis revealed that patients with high expression of CAR had worse prognosis than those with low expression of CAR（P＜0.05）.COX multivariate regression analysis demonstrated that the level of CAR is able to use as an independent prognostic factor（P＜0.05）.Conclusions CAR detection has the advantages of high efficiency,agility,economy and minimal trauma.The combined detection of CRP and Alb has an important application value in the clinical staging and prognosis of SCLC.