The treatment of sacral chordoma has been a difficult aspect of sacral tumor treatment, and our current view is to achieve effective local control through an appropriate surgical approach combined with radiotherapy to improve the quality of life of patients during the tumor control period. We have now published the results of the largest single-center case follow-up, which is important for guiding both surgical treatment and comprehensive treatment of chordoma. We need to take an objective and rational view of the place of surgery, radiotherapy and chemotherapy in the treatment of chordoma, and different treatment strategies should be used in different treatment segments to maximize the advantages of different treatment approaches and maximize the quality of life of patients while achieving local control. Chordoma, with its slow progression and high rate of local recurrence, is not life-threatening in the short term, but it has a significant impact on quality of life, and if the “degree” of surgical treatment is not grasped properly, it can be counterproductive and radiotherapy cannot achieve satisfactory local control. It is recommended that patients with chordoma, especially those with recurrence, be seen by an experienced hospital. Background】The surgical resection boundary of sacral chordoma directly determines the local control rate and long-term survival of the patient. Conditional Survival (CS) is used to describe the expected survival of patients after a period of survival, which is important to predict the oncologic prognosis of patients with different survival segments. Currently, there are no reports on conditional survival after surgical treatment of sacral chordoma. In addition, currently available functional scoring methods are difficult to accurately predict and describe sacral nerve function after sacral tumor resection and do not reflect small changes in function. The purpose of this study was to: (1) analyze the conditional survival rate of patients with sacral chordoma after surgery and clarify the characteristic changes of each factor that has an impact on prognosis over time. (2) To accurately describe sacral nerve function, including lower limb sensorimotor and diaphoretic function, in patients with sacral chordoma after surgery through a newly designed scoring system, and to clarify the relationship between sacral nerve resection segments and total postoperative nerve function. [Methods] A total of 115 patients with sacral chordoma who underwent surgery between July 2003 and December 2012 in our center were reviewed. The 5-year survival rate of our patients was calculated by the Kaplan-Meier method, and the conditional survival rate of our patients was calculated based on the static 5-year survival rate. On this basis, we analyzed the influence of prognostic factors on the conditional survival rate. The postoperative sacral nerve function of patients was assessed by a self-designed sacral nerve scoring system. The mean follow-up time for this group of cases was 59.3 months (15-130 months). [Results] The 5-year conditional survival rate of our cases decreased year by year from the first to the fourth postoperative year and increased slightly in the fifth year. The overall 5-year survival rate decreased from 80.7% at diagnosis to 62.7% at year 4, and increased to 70.9% at year 5. At diagnosis, the 5-year survival rate was significantly higher in patients with extensive and marginal resection than in those with intracapsular resection, 86.3% and 67.0%, respectively (p=0.009), and this difference was most pronounced from postoperative year 3 to year 4. Patients who had undergone surgical treatment at an outside institution were significantly less likely than patients with sacral chordoma treated initially at our institution, with 5-year survival rates at diagnosis of 64.1% and 90.2% in the two groups, respectively (p=0.012). This difference no longer existed at the 5th postoperative year, with 66.8% and 71.1% in the two groups, respectively (p>0.05). The neurological function of the postoperative patients was assessed according to a newly proposed scoring scale, which could be found to distinguish well the functional differences between the different stages of neurectomy. The overall postoperative neurological function scores were 39.5%, 60.0%, and 81.5% in patients with bilateral S1, S2, and S3 preserved, respectively. Preservation of bilateral S3 nerves significantly reduced incontinence (p=0.01) and improved voiding sensation (p=0.02) compared with preservation of unilateral S3 nerves. [Conclusion] The conditional survival rate of patients after sacral chordoma surgery decreases gradually from the first to the fourth year and improves thereafter. The two factors of surgical border and previous surgical treatment were non-linearly varying in influencing the survival rate. The level of sacral nerve root preservation can be demonstrated to be closely related to postoperative patient function according to the available scoring system.