Abstract: Objective: To study the application of intravenous catheter system in the oncology department,and to explore an effective nursing method.Methods: The 4th generation intravenous catheter sealed with single-wing,made in America,was applied to 68 patients receiving infusion therapy.The large-angle,slow and direct inserting method was applied to Group A,and the scalp needle inserting method to Group B.The relationship between the inserting methods and retaining time was studied.The veins in the neck,cubital fossa and two sides of forearm were selected in main-vein group and peripheral veins of the limbs were selected in branch-vein group.The relationship between the inserting position,the medicine and phlebitis was studied.Results: Successful retaining for more than 48 hours accounted for 88.64% in Group A,and 33.33% in group B(P<0.005);When medicine containing chemotherapy was infused,phlebitis occurred in 53.85% of the cases in the main-vein group and 87.50% in the branch-vein group(P<0.01).When medicine containing no chemotherapy was infused,phlebitis developed in(14.29%) of the cases in the main-vein group and 58.33% in the branch-vein group(P<0.05).When the vein conditions were almost the same,phlebitis occurred in(66.67%) of the cases receiving medicine containing chemotherapy and 34.62% receiving medicine containing no chemotherapy(P<0.01).Conclusions: The large angle,slow and straight inserting method may effectively prolong the retaining time of intravenous catheter and decrease the occurrence of phlebitis.Medicine containing chemotherapy,which irritates the veins greatly,is more liable to cause phlebitis.The intravenous catheter system can partly take the place of scalp needle in the oncology department.