The apicoectomy is an operation in which the root apex is removed and the adjacent periapical pathologic tissue is curetted. In this operation, there are several factors that may lead to the surgical wound infection, such as, local, systemic, environmental, endogenous and surgical factor. The systemic medical and surgical factor that may compromise patients defense are more important cause of the wound infection. The postoperative infection is likely to occur owing to poor systemic condition(especially geriatric cancer patient with operation, radiotherapy and chemotherapy), postoperative accumulation of hematoma & seroma and other contaminated factors. So, the authors established the immediate rubber drainage into the sutured wound of dental apicoectomy for the prevention of postoperative infection. The results are more favorable without the wound infection in total 31 cases of the dentistry of Dong San Medical Center & Wonju Christian Hospital.