Abstract: Objective :To investigate the polymorphism of (CAG)n repeats within androgenreceptor gene among esophageal caneer, and its possible association with esophageal caneer. Meth-ods : The number CAG repeats in exon 1 of the AR gene were measured in 41 esophageal caneerTissues (squamous cell careinomas) and 30 perieaneerous non-tumor tissues by PCR-PAGE analysis,and its association with grades of esophageal caneer determined. Results : The number of polymor-phie (CAG)n repeats ranges from 8-28 in esophageal caneer and ranges from 8-24 in perieaneerous non-tumor tissues. The number of (CAG)n repeats (≤10 Or ≥22) differed significantly betweenesophageal cancer tissues (34.1%) and pericancerous non-tumor tissues (13.3%). The change of poly-morphism of (CAG)n repeats in esophageal cancer Tissues is high event. The frequency of shortCAG repeats dropped with the increase in tumor cell differentiation while the opposite was true forthat of long CAG repeats. Conclusion : The change of polymorphism of (CAG)n repeats inesophageal cancer Tissues is high event Short CAG repeats in AR gene may signify aggressiveness.