In this study, we present a microfluidic array for high-resolution imaging of individual pancreatic islets. The device is based on hydrodynamic trapping principle and enables real-time analysis of islet cellular responses to insulin secretagogues. This device has significant advantages over our previously published perifusion chamber device including significantly increased analytical power and assay sensitivity, as well as improved spatiotemporal resolution. The islet array, with live-cell multiparametric imaging integration, provides a better tool to understand the physiological and pathophysiological changes of pancreatic islets through the analysis of single islet responses. This platform demonstrates the feasibility of array-based islet cellular analysis and opens up a new modality to conduct informative and quantitive evaluation of islets and cell-based screening for new diabetes treatments.