Abstract： Objective To investigate the dynamic changes of peritoneal catheter of ventriculoperitoneal shunt (V- P shunt) prospectively,and to determine simple,effective disposal method of peritoneal catheter.Method From Jan 2007 to Oct 2010,consecutive 40 patients with hydrocephalus were treated by V - P shunt.All patients were operated through puncture of frontal horn of lateral ventricle.And 4 cm straight abdominal incision under xiphoid was made and after shunt system had been connected well,the abdominal catheter was put into peritoneal cavity through 3 mm incision of peritoneum.Head CT scans were regularly made at the 1st,3rd and 7th day after shunt to determine the intracranial state for all patients,and abdominal X - ray plain films were also obtained to confirm the position of peritoneal catheters at the same time.All the clinical data and results of follow - up were reviewed.Results Dynamic head CT scans showed good results of V - P shunt after surgery in all cases.And abdominal X -ray plain films at the 1 st day after operation showed peritoneal catheter was located in pelvic cavity in 31 cases and lower abdominal cavity in 5 cases.At the 3rd day and 7th day after operation,the numbers of peritoneal catheter located in pelvic cavity were 35 and 39 respectively.Among these patients,a large acute subdural hematoma occurred on the same side of V - P shunt at the 5th day after operation.This patient was discharged with GCS 6 as his family refused decompressive craniectomy.The remaining 39 patients were discharged with average hospital - stay time of 11 ± 4 days after shunt.On follow - up,1 patient developed peritoneal infection one year later.After the infection was controlled,he was changed to ventriculo- atrial (V -A) shunt.There was no shunt- related complication occurred on the others during 1 -24 month follow - up periods.Conclusion V - P shunt through small straight incision under xiphoid could reduce surgical injury,shorten the operating time and obtain good Results.Dynamic observation of the location of peritoneal catheter by abdominal X - ray plain film is a simple and practical method.The peritoneal catheter will located in pelvic cavity at the 1 st day after shunt in vast majority.There is no special management for peritoneal catheter in V - P shunt in required.