Objective　To investigate CT imaging features of sacroiliac joint in uSpA female patients of child-bearing age.　Methods　The sacroiliac joint CT of 60 uSpA female patients of child-bearing age was analyzed. The width of sacroiliac joint space and the thickness of sacroiliac cortex were measured, the clearness of sacroiliac joint space, the smooth of sacroiliac cortex edge and the bone density under the cortex were observed.　Result　The sacroiliac joint spaces were blurred in 53% uSpA female patients of child-bearing age. The width of sacroiliac joint space of uSpA female patients of child-bearing age was less than 2 mm in 68.5% of the cases. It was fuzzy on the surface of unilateral or bilateral joint, rough on the edge of sacroiliac cortex, uneven in densities of cartilage in 95% uSpA female patients of child-bearing age, 20% articular surfaces were classified as graded 3. The sacroiliac cortex became thicker with age. The erosions of the articular surface and the cortex thickened changes were more severe in the iliac side. 36.6% of the articular cavity in the normal child-bearing age women had linear, dotted and gasiform low density shadow.　Conclusion　The incidence and extent of sacroiliac joint spaces blurring, narrowing of the joint space,erosion of articular surface and grade, and bone proliferation under surface are higher in uSpA female patients of child-bearing age than that in normal child-bearing age women. The incidence of sacroiliac joint vacuum phenomenon is higher in uSpA female patients and is related to uSpA. For normal women of child-bearing age with abnormal sacroiliac joint changes, they should be determined whether the arthritis exists based on history, laboratory tests and MR. For normal women of child-bearing age with symptoms but being by graded CT as 0 or 1, MR should be further undertaken to visualize early active inflammation.