Objective:To investigate the diagnostic efficacy of serum tumor markers for esophageal squamous cell carcinoma(ESCC)in northeast Sichuan province.Methods:The expression of miR-222-5p in esophageal tissues(observation group)and serum of 46 ESCC patients and 46 healthy subjects(control group)was detected by fluorescent quantitative PCR,and the relationship between the expression of serum miR-222-5p in ESCC and clinicopathological features was analyzed.Differential expression of miR-222-5p in tumor tissues and serum samples was analyzed by constructing receiver operating characteristic(ROC)curves to assess its diagnostic value for ESCC.Results:The serum level of miR-222-5p in the observation group was higher than that in the control group[(1.76±0.99)vs.(1.24±1.08),t=-2.396,P=0.019].The serum miR-222-5p level in ESCC stage Ⅰ was lower than that in ESCC stageⅡ and ESCC stage Ⅲ[(1.01±0.19)vs.(1.78±0.31)vs.(2.59±0.44),F=44.793,P＜0.001].The level of serum miR-222-5p in ESCC patients with distant metastasis was higher than that in ESCC patients without distant metastasis[(1.02±0.21)vs.(0.60±0.34),t=2.090,P=0.043].The serum miR-222-5p level of ESCC patients with lymph node metastasis was higher than that of ESCC patients without lymph node metastasis[(1.04±0.32)vs.(0.79±0.39),t=2.223,P=0.032].There was no significant difference in serum miR-222-5p levels between male and female ESCC patients[(1.01±1.33)vs.(1.07±1.61),t=-0.123,P=0.903].There was no significant difference in serum miR-222-5p levels between ≤ 65 years old and＞65 years old ESCC patients[(1.09±0.53)vs.(1.06±0.67),t=0.145,P=0.885].The serum miR-222-5p level in the pre-ESCC group was higher than that in the post-ESCC group[(2.46±1.65)vs.(1.85±0.99),t=2.141,P=0.035].ROC curve showed that when serum miR-222-5p was 0.393,the diagnostic efficacy of ESCC was the highest,the sensitivity was 58.70％,and the specificity was 80.60％.When miR-222-5p of tumor tissue was 0.435,the diagnostic efficacy of ESCC was the highest,and the sensitivity was 65.20％and the specificity was 78.30％.Conclusion:miR-222-5p has a certain predictive effect on the occurrence and development of ESCC in northeast Sichuan province,and shows moderate diagnostic efficacy.