This study aims at observing the expression of activated Src tyrosine kinase in esophageal squamous cell carcinoma (ESCC), and exploring the relationship of Src tyrosine kinase with the occurrence and progression of ESCC. Immunohistochemistry, immunofluorescence, and immunoblotting are employed to investigate the expression of Src tyrosine kinase in the ESCC tissue. Cellular immunofluorescence is used to measure the expression of activated Src tyrosine kinase in TE1 and TE9 cell lines of human ESCC tissues and EPC1-htert and EPC2-htert cell lines of esophageal epithelial cells. Src tyrosine kinase is overexpressed in ESCC tissue and underexpressed in normal esophageal mucosa. Furthermore, it is overexpressed in the TE1 and TE9 cell lines of human ESCC tissue and underexpressed in the EPC1-htert and EPC2-htert cell lines of esophageal epithelial cells. Src tyrosine kinase shows a higher expression in human ESCC tissue than in normal esophageal mucosa. The difference is statistically significant (P < 0.05). The activation of Src tyrosine kinase plays an important role in the occurrence and development of ESCC.