Objective To investigate the clinical significance of quantitative analysis of serum CYFRA21-1 for diagnosis and tumor TNM and clinical stages in nasopharyngeal carcinoma (NPC). Methods Pretreatment serum CYFRA21-1 in 112 firstly diagnosed NPC patients and 93 benign controls were measured by ELISA. Results The serum CYFRA21-1 positive rate of NPC was 66.1%.The level and positive rate of serum CYFRA21-1 in NPC group are significantly higher than those in controls respectively(P<0.05).The level and positive rate of serum CYFRA21-1 in T4, N3 and M1 group were significantly higher than those in T1,N2,N1,N0 and M0 group, respectively(p<0.05).The level of serum CYFRA21-1 in T3+T4 group was significantly higher than that in T1+T2 group(p<0.05).In the clinical staging,the level and positive rate of serum CYFRA21-1 in IV group were significantly higher than those in II,III group respectively(p<0.05),and the level of serum CYFRA21-1 in the IVb subgroup were also higher than the IVa subgroup(p<0.05).The level of serum CYFRA21-1 in NPC group positively correlated with the T,N classification and clinical stages. Conclusion Pretreatment serum CYFRA21-1 level has clinical value for diagnosis,differential diagnosis,tumor staging in NPC.