Objective To evaluate the diagnosis and the clinical application value of serum soluble MICA protein in patients with esophageal carcinoma or cardiac carcinoma.Methods The serum sMICA was concomitantly determined by ELISA in 50 preoperative patients with esophageal carcinoma or cardiac carcinoma and 20 healthy controls.Results The level of serum sMICA in patients was significantly higher than that in controls[(322.42±9.09)pg/ml,(176.00±11.69)pg/ml](P＜0.01).In patients with TNM stage Ⅱ,Ⅲ,Ⅳ,the level of serum sMICA increased significantly in order(P＜0.05).In patients with lymph node metastasis.the level of serum sMICA was significantly higher than that without lymph node metastasis.The level of serum sMICA in patients with imbricate carcinoma was higher than patients with glandiform carcinoma.In patients with TNM stageⅢ.the level of serum sMICA after operation was significantly lower than that before operation.ConclusionSerum sMICA could be an assistant indicator for esophageal carcinoma or cardiac carcinoma.sMICA could be considered as a new tumour symbol to evaluate the biological behavior and prognosis of esophageal and cardiac carcinoma.