Purpose:To evaluate intraoperative block of abdomial aorta(BAA) in surgery of sacral and pelvic tumors as a useful adjuvant technique.Methods:Of 164 cases of pelvic tumor who underwent resections and hemisections, the procedures in 94 cases were non block of abdominal aorta(NBAA);in 109 cases of sacral tumors various extents of acrectomy was done,53 cases had NBAA,56 cases had BAA.Results:In the pelvic tumor group, the size of tumors for BAA were on the average bigger than NBAA by 0.8 cm, the operation was shortened by 2 h, the dose of hemorrhage decreased by 2 200 ml. The complications of operation were reduced by 6.3%, death rate reduced by 4.6%. In the sacral tumor group, the size of tumors for BAA were on the average bigger than NBAA by 0.7 cm, the operation was shortened by 1 h and 40 min, the dose of hemorrhage decrease by 1 600 ml. The complications of operations were reduced by 23%, death rate reduced by 7.5%.Conclusions:The adoption of BAA adjuvant technique can reduce the intraoperative hemorrhage,the death rate, and the complications of operation, while also shortening the surgical operating time, and is a valuable clinical technique. [