Abstract: Objective：To discuss the characteristics and treatment of syphilitic aortic aneurysm by analyzing the situation of syphilitic aortic aneurysm in the cardiovascular surgery. Methods：Twenty patients who were diagnosed as syphilitic aortic aneurysm from October 2010 to August 2018 in Changhai Hospital, including 12 non-emergency patients and 8 emergency patients. All the patients showed positive results in serological test for syphilis and obvious aortectasia according to the computed tomographic angiography. For non-emergency patients, antibiotic therapy combined with hormonotherapy were given pre-operatively to reduce the serum syphilis level and prevent the incidence of Jarisch-Herxheimer reaction. For the emergency patients, surgeries were given in time to prevent death from aortoclasia. Results：Of the 20 patients receiving treatment (emergency or non-emergency surgery), ventilator assist time, ICU stay time, hospital stay, 24 h and 48 h postoperative white blood cell count and neutrophil ratio, and postoperative infection were better than those of patients underwent conventional aneurysm surgery. The pathological staining of vascular wall showed that infiltration inflammatory cells infiltrated and mainly located around the nourishing blood vessels. Postoperative follow-up results showed that patients in both groups achieved good long-term results after surgery. Conclusions：For patients with aortic aneurysm, the possibility of syphilitic aortic aneurysm should be fully considered. For the non-emergency patients, regular pharmaceutical and surgery therapy should be the first choice. For those whose aortic diameter bigger than 6 cm or suffer aortic dissection, emergency operation without antibiotic and hormone therapy could be more safe, feasible, and effective.