Objective To explore ways to decrease peripheral vascular complications during parenteral nutrition through peripheral veins. Methods According to the support sequences of giving peripheral parenteral nutrition, ninty perioperative cases were randomly divided into low(20. 3 kPa·h-1 ),medium(27. 1 kPa·h-1 ) and high(33. 9 kPa·h-1 ) osmotic pressure rates(n=30 in each group). The infusion pump was used to control the rate of infusion. The total parenteral nutrient was infused through BD24G venous indwelling needles. The pain ratings at injection sites were evaluated after parenteral nutrition everyday,the incidences of phlebitis were observed three days later after removing the indwelling needles. ResultsUnder the low osmotic pressure,the pain was mild,while for the medium osmotic pressure,the pain became more obvious. The pain was aggravated obviously under high osmotic pressure. There were only two cases of over grade-II phlebitis under low osmotic pressure rate,9 cases under medium osmotic pressure rate and 14 cases under high osmotic pressure rate, in which a grade-Ⅲ phlebitis developed. Conclusion Decreasing the osmotic pressure rate through peripheral venous is an effective method to avoid or reduce the incidences of peripheral vascular complications with the peripheral parenteral nutrition support.