Objective To explore the effects of different flushing and sealing procedures on blood pressure fluc-tuation in patients receiving norepinephrine(NE) via micro-pump. Methods A total of 40 cases of critically ill pa-tients receiving intravenous infusion of NE via micro-pump,were randomly divided into two groups(20 cases in each group) from March to September,2016. For the experimental group,the liquid medicine in central venous catheter was sucked out,followed by flushing or sealing the tube according to conventional operation method. For the control group,conventional operation method was used to flush or seal the tube. The effects of two methods on arterial blood pressure were compared. Results Overall 423 flushing and sealing events were recorded among 40 cases in this study (209 in the experimental group and 214 in the control group). The fluctuation of blood pressure was small in the experimental group,while patients in the control group had significant fluctuation of blood pressure(P<0.05). Conclusion The new method that sucking liquid medicine out of the central venous catheter before flush-ing or sealing the tube followed by flushing or sealing using conventional operation method can reduce the risk of sudden increase in blood pressure for patients receiving small dose infusion with micro-pump.