The dynamic behavior of bed for regeneration of cerium oxide high temperature gas desulfurization sorbent under the atmosphere of O₂ was investigated in the fixed bed micro-reactor. O₂ concentration during the regeneration can be detected by an oxygen analyzer, and the sulfur content of sorbent in the bed was test using sulfur analyzer. The effects of O₂ concentration, regeneration temperature on the dynamic behavior of bed for regeneration of CeO₂ desulfurization sorbent were discussed. According to the experimental results, the length and movement speed of regeneration zone are calculated. The results showed that the increase of O₂ concentration in inlet gas obviously improves the movement speed of regeneration zone in bed for CeO₂ desulfurization sorbent, and the increase of regeneration temperature can decreased the length of the regeneration zone and improved the movement speed of the regeneration zone. The increase of regeneration temperature had a better effect on the improvement of bed utilization of sorbent than that of O₂ concentration.