Background and Objective Diabetes has become a common healthy problem in the world, which is an autoimmune disease mediated by infl ammatory cytokine. Infl ammation plays an important role in the pathogenesis of diabetes and macrovascular complications. Chitinase-3-like protein-1 (YKL-40) is a new infl ammatory factor, which can infl uence the level of other infl ammatory markers and related to the development of cardiovascular diseases. This study aims to investigate the level of YKL-40 in patients with diabetes and impaired glucose tolerance. Correlation between YKL-40 and blood glucose, lipids, high sensitivity C-reactive protein, IMT was compared.