Abstract: Objective 　To explore the change of DNA content, cell cycle distribution and expression of cell cycle regulatory elements in esophageal canceration course. Methods 　30 cases of esophageal carcinoma and corresponding adjacent noncancerous tissue were detected quantitatively by propidium iodide ( PI) stain and indirect immunofluorescence of fluorescein isothiocyanate ( FITC) using flow cytometry ( FCM) equipment . Results 　Comparing with normal epithelium and dysplasia tissue, DNA content and heteroploid cells increased significantly in esophageal carcinoma. The percentage of cells in G₀ / G₁ phase decreased while which increased in G₂ / M phase sharply, the proliferation index ( PI) enhanced in carcinoma than in corresponding adjacent noncancerous tissue. Expression of cyclinE、cdk2 、p53 、E₂ F proteins increased obviously while p21^WAF1 expression decreased in esophageal carcinoma. There are significant positive correlations among the expressions of cyclinE、cdk2 、p53 、E₂ F proteins each other, but there is a negative correlation between p21^WAF1 protein and each of them. Conclusion 　During the esophageal canceration course, DNA content and heteroploid rate increased significantly. Cell cycle dist ribution changed obviously. Expressions of relevant cell cycle regulatory element s were abnormal.