Abstract: The paper determined serum copper,zine,iron,manganese,calcium levels in esophagus cancer(130 cases). stomatch cancer(100cases). rectal cancer(6Ocases)and liver cancer(22 cases)and various digestive tract benign discases(56 cases). The results showed that serum copper,iron levels,Cu/Zn ratio were significantly higher and zine,calcium levels were significantly lower in digestive tract cancer than in healthy subject and in other digestive tract benign discases(P<0. 05～P<0. 001),stage Ⅲ～Ⅳ and metastatic carcinoma patients copper level,Cu/Zn ratio were significantly higher and zinc level was significantly lower than that in stage Ⅰ～Ⅱ(P<0. 05～P<0. 001),Cu/Zn ratio have a sensitivity 72% on esophagus cancer,68% on stomach cancer,59% on rectal cancer,80% on liver cancer,Cu/Zn ratio can be used as a diagnosis in patients with digestive tract cancer. And it has a certain role in recognizing digestive tract cancer from high risk group. Multi-variable logistic regression analysis showed serum Cu,Cu/Zn ratio elevation maybe the dangerous factors of digestive tract cancer and serum zinc,calcium may have inhibition action to digestive tract cancer.