Objective To investigate the relationship between promoter methylation of RASSF1A gene and laryngeal squamous cell carcinoma.Methods A methylation-specific PCR was performed to detect the promoter methylation of RASSF1A gene in 48 tumor tissues,48 corresponding normal tissues and 48 normal blood plasma.The expression of RASSF1A protein was determined by means of Western blotting.Results The methylation in RASSF1A gene was detected in 34(70.83%) tumor tissue samples,11(22.92%) corresponding normal tissue samples and 6(12.50%) blood plasma samples,respectively.The methylation degree of tumor tissue was higher than that of corresponding normal tissues and normal blood plasma(P