The progress of clinical study and adverse events of thiazolidine rosiglitazone were reviewed in this article. The clinical effect iveness of rosiglitazone in combination with other antidiabetic agents was better than that of rosiglitazone as monotherapy. Furthermore, the patients with type-2 diabetes mellitus administered with rosiglitazone, who had been previously treated with dietotherapy only, had better effect iveness than those who had been previously treated with one or more other antidiabetic agents. In addition, rosiglitazone has light adverse events and does not cause significant hepatic dysfunction.