Objective To investigate the risk factors of ventriculo-peritoneal shunt tube blockage after surgery in infant with hydrocephalus and the effect of preoperative administration of umbilical cord mesenchymal stem cells(Mesenchymal stme cells,MSC) on the incidence of this complication.Methods A retrospective analysis was conducted in 125 cases of infant with hydrocephalus to evaluate the occurrence of shunt blockage during the follow-up of 2 years after ventriculo-peritoneal drainage.Further,the incidence and its associated factors in 11 cases who received intravenous infusion of MSC treatment preoperatively were also analyzed.Results The clinical risk factors included preoperative cerebrospinal fluid cell count,cerebrospinal fluid protein content,age,terminal of location drainage tube and serum albumin concentrations orderly.MSC treatment significantly increased serum albumin level and decreased the occurrence of drainage tube obstruction(1/11 vs.53/114,P<0.01).Conclusion Preoperative infusion of MSC can increase the level of serum albumin and reduce post-operative complications.