Objective To explore the mRNA and protein expression of ECRG4 in laryngeal squamous cell carcinoma (LSCC) and its methylation level in LSCC tumor tissue, and to analyze its clinical significance.Methods The expression of ECRG4 in head and neck tumors was analyzed from the Human Protein Atlas (HPA) and Gene Expression Profile Interactive Analysis (GEPIA) databases. Tissue samples of 15 patients with primary LSCC and adjacent normal tissue samples were collected. Real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression of ECRG4 mRNA in the samples, and Western Blot was used to detect the protein expression in the tissues. Methylation-specific PCR (MSP) and sequencing analysis were used to detect the methylation level of ECRG4 promoter. Compare the correlation between ECRG4 mRNA expression and methylation level and clinicopathological characteristics of LSCC patients.Results HPA and GEPIA analysis showed that ECRG4 expression was decreased in head and neck squamous cell carcinoma. The results of RT-qPCR and Western Blot showed that ECRG4 mRNA and protein expression in LSCC patients were lower than those in adjacent normal tissues(P<0.001). And the results of sequencing analysis indicated that the methylation level of ECRG4 promoter was significantly increased in LSCC tumor tissues (P<0.001). The high expression level of ECRG4 mRNA was correlated with stage III、IV, lymphatic metastasis, recurrence, and G2、G3 grade in LSCC patients (P<0.05), while the methylation level of ECRG4 promoter in LSCC patients with stage III、IV, recurrence and G2、G3 grade was significantly increased (P<0.05).Conclusions The expression level of ECRG4 is decreased, and the methylation level of ECRG4 increased in LSCC. The changes of ECRG4 are more obvious in patients with stage III、IV, recurrence and G2、G3 stage, which provides a theoretical basis for the subsequent study of LSCC.