This study aimed to investigate the physicochemical properties and antidiabetic effects of a polysaccharide obtained from corn silk (PCS2). PCS2 was isolated and the physicochemical properties were characterized. The hypoglycemic effects were determined using the high-fat diet and streptozocin induced type 2 diabetic mellitus (T2DM) insulin resistance mice. The results showed that PCS2 was a heteropolysaccharide with the average molecular weight of 45.5 kDa. PCS2 was composed of D-galactose, D-mannose, D-(+)-glucose, D-(+)-xylose, L-arabinose and L-rhamnose. PCS2 treatment significantly reduced the body weight loss, decreased blood glucose and serum insulin levels, and improved glucose intolerance (P < 0.05). The levels of serum lipid profile were regulated and the levels of glycated serum protein, non-esterified fatty acid were decreased significantly (P < 0.01). The activities of superoxide dismutase, glutathione peroxidase and catalase were notably improved (P < 0.05). PCS2 also exerted cytoprotective action from histopathological observation. These results suggested that PCS2 could be a good candidate of functional food or medicine for T2DM treatment. (C) 2017 Elsevier Ltd. All rights reserved.