【Abstract】 Objective To explore the possibility of its potential as a potential tumor marker for early diagnosis of lung cancer, through the detection of micro miR1265p expression in the serum of patients with lung cancer. Methods RTqPCR analysis was used to detect 55 cases of lung cancer patients and 21 healthy people, 32 cases of patients with benign lung disease in serum miR1265p levels. The statistical comparison t test was performed using Levene test and variance equation of the mean equation. The diagnostic efficacy of indexes was analyzed by R0c curve. Result The sign of the serum of lung cancer patients in the miR1265p group was significantly higher than that of tumor markers of patients with benign disease in healthy people and Lung Group (F=1481, P< 0001; t=391df=789 bilateral P< 0001). ROC area under the AUC curve was 0666. The sensitivity was 661%, and the specificity was 717%. Conclusion R1265p is highly expressed in tumor patients. The detection of serum in the diagnosis of lung cancer has a certain clinical value, and has a high sensitivity and specificity.