Hyaluronic acid (HA) is an extremely ubiquitous polysaccharide of extracellular matrix in body and plays various biological roles. In this study, cell viability, insulin secretion and cytosolic free Ca2+ concentration were investigated in HIT-T15 cells after HA-treatment. The cell viability was determined by the MTT assay while the insulin secretion was detected by ELISA technique. The Flou-3/AM was applied to probe intracellular free calcium concentration. HA (0.25, 0.5, 1.0 mg/dish) increase insulin secretion in the 3 or 25 mM glucose-stimulation for 4 h. Cytosolic Ca2+ fluorescent intensity in HA-treatment groups (0.25, 0.5, 1.0 mg/dish) is significantly higher than that in control group. This study implied that the increasing of insulin secretion of HIT-T15 cells by HA-coating result from the enhancement of cytosolic Ca2+. And these data also provide some information on design biocompatibility when HA used as a biomaterial for bioartificial pancreas.