ATM protein anticipates in the initiation of the DNA repair signal pathway and also mediates cell cycle arrest and repair. ATM deficiency predictably results in radiosensitivity, germ cell degeneration, chromosomal instability, immunodeficiency, and an extreme predisposition to tumors. Moreover, studies found that ATM is the upstream gene of the p53 pathway and would phosphorylate p53 directly after DNA damage, which would suppress tumorigenesis. Expression of ATM and p53 in 167 pancreatic cancer and 101 control specimens, benign lesions, and normal pancreata were detected by high-throughput tissue microarray and immunohistochemistry while seeking the role of ATM in the initiation and development of pancreatic carcinoma as well as its relationship with p53. We found that the positive rates of ATM and p53 expression in pancreatic carcinoma and its relative control specimen were 67.7% (113/167) and 82.2% (83/101) (P<0.05) and 57.5% (96/167) and 5.0% (5/101) (P<0.01), respectively. ATM positive staining is significantly relative to age and infiltration (P<0.05), while the expression of p53 was significantly associated with tumor differentiation, lymph node metastasis, and nerve infiltration (P<0.05). Expression of ATM and p53 was positively correlated. These findings suggest that expression of ATM deficiency may increase the transformative ability of pancreatic cancer cells. ATM may also cooperate with p53 in the repair of cell damage. ATM protein anticipates in the initiation of the DNA repair signal pathway and also mediates cell cycle arrest and repair. Further, studies have found that radiosensitivity, germ cell degeneration, chromosomal instability, immunodeficiency, and an extreme predisposition to tumors. is the upstream gene of the p53 pathway and would phosphorylate p53 directly after DNA damage, which would suppress tumorigenesis. Expression of ATM and p53 in 167 pancreatic cancer and 101 control specimens, benign lesions, and normal pancreata were detected by high-throughput tissue microarray and immunohistochemistry while seeking the role of ATM in the initiation and development of pancreatic carcinoma as well as its relationship with p53 of Were that the positive rates of ATM and p53 expression in pancreatic carcinoma and its relative control specimen were 67.7% (113/167 ) and 82.2% (83/101) respectively (P <0.05) and 57.5% (96/167) and 5.0% (5/101) respectively While the expression of ATM and p53 was positively correlated with tumor differentiation, lymph node metastasis, and nerve infiltration (P <0.05), the expression of ATM and p53 was positively correlated. findings suggest that expression of ATM deficiency may increase the transformative ability of pancreatic cancer cells. ATM may also cooperate with p53 in the repair of cell damage.