Abstract: Objective :To discuss the experience and efficacy of the trans -single nostril transsphenoidal microsurgical therapy for pituitary adenamas. Methods : One hundred and thirty-three patients with pituitary adenoma were treated microsurgically by the trans-single ostril transsphenoidal approach, from January 1995 to December 2003, including 25 cases of microadenamas, 45 macroadenamas and 63 giant adenamas. Fifty-four aged patients suffered with physial hypofunction. Pathological classification and endocrine examination confirmed that 63 cases were PRL adenomas, 15 GH adenomas, 9 ACTH adenomas, 10 multfunctional adenomas and 36 nofunctional adenomas. Results : One hundred and five cases underwent total resections, 16 subtotal removals and 12 partially removed.There were 103 cases of healing patients, 21 remissions, 6 relapses, 1 death and 2 loss of follow-up with 0.57.5 years of follow-up. Conclusions :This approach with practised microsurgical skill for deep tumors is suitable for pituitary adenomas, especially for aged patients, with minimally invasive, quick postoperative recovery and good curative effect.