To study the clinical significance of the novel tumor marker--CYFRA21-1 in patients with esophageal cancer.The CYFRA21-1 level in serum of 84 patients with a definite diagnosis of esophageal cancer was examined 10 days before and after operation by ELISA. A 3 years' follow-up was conducted to the survival of patients.(1) The CYFRA21-1 level was > 3.3 ng/ml in 72.6% of the patients (61/84). (2) The serum CYFRA21-1 level decreased significantly after operation in patients at stage III or with high differentiation (P < 0.05). (3) The difference between pre- and post-operative serum CYFRA21-1 levels was statistically significant in patients who had undegone radical operation, and was not in patients who had undergone palliative operation. (4) In addition to stage (P < 0.05) and type of operation (P < 0.05), the difference of CYFRA21-1 level before and after operationwas closely related to the prognosis (P < 0.05).CYFRA21-1 is a useful marker in diagnosis and prediction of prognosis of esophageal cancer.