Abstract: The thermal stress of concrete frame structures with plane rings under a seasonal temperature difference is studied. The paper analyzes the theoretically structure deformation, radial stress and circumferential stress of beams and slabs, and the column stress of ring-shaped concrete frame structures. An example was given to verify the analysis. The results show that the focus of crack control on a ring-shaped concrete frame structure is the circumferential tensile stress of beams and slabs as well as the stress in columns. The value of the circumferential tensile stress is proportional to a constraint coefficient of a radial displacement. The circumferential stress gradually increases from the outer ring to inner ring so that a radioactive penetrating crack may arise starting from the inner ring. The moment of columns, particularly side columns, is considerable and a serious flexural crack or failure may occur. The reinforcement must be strengthened to meet crack control requirements.