Abstract: Objective : To study the expression of Id-1 and PTEN protein in ESCC and their functions in theangiogenesis and prognosis of ESCC. Methods : We used immunohistochemistry to detect the expression ofId-1 and PTEN in 131 surgical specimens of ESCC and 40 samples of normol esophageal tissue. Therelationship of Id-1 and PTEN with MVD was analyzed after assessing the microvessel density (MVD) inESCC depending on CD-34 expression. The relationship of these indices with the prognosis was analyzed byKaplan-Meier life table method and COX regression model. Results : The positive expression rate of Id-1 was83.2% (109/131) in ESCC and 5% (2/40) in the incisal edge of normal tissues, with a significant difference (P<0.01). The expression of Id-1 was not correlated with age, sex, infiltration degree and lymphatic metastasis(P<0.05). Id-1 expression was positively correlated with the degree of cancer differentiation and MVD (P<0.01) and was negatively correlated with the prognosis of patients. The positive expression rate of PTEN was62.6% (82/131) in ESCC and 97.5% (39/40) in the incisal edge of normal tissues, with a significant difference(P<0.01). The expression of PTEN was not correlated with age, sex, and degree of cancer differentiation, butwas obviously correlated with infiltration degree and lymphatic metastasis (P<0.05). PTEN expression wasnegatively correlated with MVD (P<0.01) and was positively correlated with the prognosis of ESCC. COXregression model showed that Id-1 and PTEN expression and infiltration degree were all important factorsthat can predict the prognosis of ESCC. Conclusion : High expression of Id-1 or down-regulated expression ofPTEN may have a a crucial effect on promoting the genesis of ESCC and its angiogenesis. Id-1 may play amore important role in the angiogenesis of ESCC. Both Id-1 and PTEN are independent factors of the prognosis of prognosis of ESCC.