Abstract： Objective To discuss the clinical characteristics, treatment strategy of the cavernous sinus residual tumor (CSRT) accompanying the empty sella syndrome after treatment of invasive prolactinomas. Method Data from 18 patients with CSRT were retrospectively reviewed. Nine patients initially received bromocriptine as primary treatment; nine patients had initially undergone transcranial or transsphenoidal microsurgery and then received bromocriptine or adjuvant radiotherapy. Results During an average follow-up period of 55 months, serum PRL levels of 8 patients were in normal range and those of 10 patients were above the normal level. Visual symptoms improved in 7 patients while deteriorated in 2 patients. Fourteen patients had a secondary empty sella due to tumor shrinkage. Of those 14 patients, seven still had elevated PRL levels; five had optic ehiasmal herniation by different degrees (P<0.05). Seven of these 18 patients maintain their PRL levels normal with low-dose bromocriptine treatment without significant clinical symptoms. Conclusions After treatment of invasive prolactinomas, great attention should be focused on CSRT accompanying the empty sella, especially in cases with optic chiasmal herniation. CSRT with PRL normalization and no pressure symptoms can be treated with low-dose of bromocriptine so as to achieve long-term tumor volume control and endocrine control.