The invention discloses a method for using a DEPDC1B gene and an expression product of the DEPDC1B gene as a molecular marker for early diagnosing esophagus cancer .An experiment shows that the DEPDC1B gene is differently expressed in esophagus cancer patients and normal esophagus tissues, and whether a tested person suffers from esophagus cancer or not can be judged by detecting the expression condition of the DEPDC1B gene in the esophagus tissue of the tested person .In addition, the invention discloses a method for using the DEPDC1B gene and the expression product as a target for treating esophagus cancer, and the method is used for guiding researching and development of new medicine.