Objective To study the correlation between serum cytokeratin 19 fragment(CYFRA21-1), human epididymal protein 4(HE4) levels and pathological characteristics, prognosis of patients with lung cancer. Methods A total of 112 patients with lung cancer treated in the hospital were enrolled as lung cancer group between February 2019and May2021, while other 92 healthy volunteers undergoing physical examination in the hospital during the same period were enrolled as control group. All were tested for levels of serum CYFRA21-1 and HE4. They were followed up for 2 years after treatment. According to prognosis, patients were divided into good prognosis group and poor prognosis group, levels of serum CYFRA21-1 and HE4 between the two groups were compared. The correlation between serum CYFRA21-1, HE4 levels and pathological characteristics, prognosis of lung cancer patients was analyzed. Results The levels of serum CYFRA21-1 and HE4 in lung cancer group were significantly higher than those in control group(P＜0.05). There was no significant difference in levels of serum CYFRA21-1 and HE4 among patients with different genders, age and pathological types(P＞0.05), but there were significant differences among patients with different clinical staging and metastasis(P＜0.05).The levels of serum CYFRA21-1 and HE4 were positively correlated with clinical staging(P＜0.05). The levels of serum CYFRA21-1 and HE4 in poor prognosis group were significantly higher than those in good prognosis group(P＜0.05). ROC curves showed that when serum CYFRA21-1 was over 6.43 μg/ml or HE4 was over 73.12 pmol/L, the risk of poor prognosis in lung cancer patients was increased. AUC and sensitivity of CYFRA21-1 combined with HE4 were significantly greater than those of single index(P＜0.05). Conclusion The levels of serum CYFRA21-1 and HE4 are significantly increasedin patients with lung cancer, which are closely related to clinical staging. The combined detection of the above-mentionedserum indexes can better predict the prognosis of patients with lung cancer. Clinically, monitoring levels of serum CYFRA21-1 and HE4should be paid attention to so as to provide reference for conditions and prognosis determination of lung cancer.