Oxide superconductors are exposed to kinds of atmospheric variation. Temperature change between the cryogenic and the room temperature is one of the most probable situations to occur in real application. Repetitive temperature cycles may cause the damage in the superconducting bulk, thus the effect of the exposure to repetitive temperature change is studied. 300 times repetition of temperature changes between 70 and 300 K are applied to an YBCO sintered bulk. The specimen is exposed to the homogeneous external magnetic field generated by Helmholtz coils, and the surrounding magnetic fields are measured. The calculation of shielding effect is consisted of the integration of the flux density distribution and the standardization by the normal conducting results. As the results, 10% degradation of magnetic shielding effect was estimated by the calculation. However, no apparent difference in SEM appearance, X-ray diffraction profile, and fluoroscopic content analysis was observed between the specimens before and after the experiments. Correlation between the temperature increase rates and the degradation speed was observed. Further and detailed experiments are required.