Abstract: Objective: To study the expression of CDC2 and MCM2 in human esophageal squamous cell carcinoma(ESCC),and to investigate their relationship with clinicopathological parameters and their role in the genesis and development of ESCC.Methods: The expressions of CDC2 and MCM2 in 90 cases of human esophageal squamous cell carcinoma,28 cases of adjacent normal tissues and 16 cases of severe dysplasia were determined using Elivision immunohistochemical technique.Results: The positive rates of expressions of CDC2 and MCM2 in ESCC were higher than that in the normal tissue(P<0.01);the expression of CDC2 was associated with the clinical staging in ESCC(P<0.05).The expression of MCM2 was associated with the differentiation grade and metastasis of lymph nodes in ESCC(P<0.05).And there was negatively correlation between CDC2 and MCM2.Conclusions: CDC2 and MCM2 play a crucial role in cell cycle regulation.They together promote the genesis and development of ESCC,and may serve as an important index in early diagnosis of ESCC.