Abstract： Objective To study the influence factors and repair of cerebrospinal fluid(CSF)rhinorrhea created at the time of transsphenoidal pituitary adenomectomies.Method 70 patients with CSF rhinorrhea found during transsphenoidal operation were investigated in this retrospective study.28 patients were males and 42 females.Their age were 21～65 years old,mean age was 35.8 years old.Mean history was 3.1 years.Pituitary adrenocorticotropic hormone(ACTH)-releasing adenomas were diagnosed in 17 patients,pituitary growth hormone(GH)-releasing adenomas were diagnosed in 14 patients,prolactinomas in 6 cases,and non-functional adenomas in 11 cases.Transsphenoidal operation was performed on all patients.CSF leaking was found during transsphenoidal operation.Tissue grafts,fibrin glue,lumbar drain placement or bedrest for 3-10 days were used in repairing CSF leakage.Results There was no postoperative CSF rhinorrhea.Conclusions The incidence of CSF leakage during transsphenoidal operation is 10.8%.It is higher in pituitary ACTH releasing adenomas because the pituitary anterior lobe tissue around adenomas is partly removed.It is safe and effective to repair CSF leakage by using tissue grafts,fibrin glue and bed rest.Lumbar drain placement should be used for serious CSF leak during operation.