We propose a novel HDR imaging method using a coded electronic shutter that allows capturing spatially varying exposures simultaneously in a single image. Previous HDR imaging approaches have difficulties in capturing moving objects and handling camera shakes, since they assume the target scenes to be static. Special imaging devices such as exposure-filtering masks could reduce motion artifacts, but manufacturing costs have limited their practicality. Using the proposed framework, we extend the dynamic range of an input image without extracting the subimages for different exposures while preventing jaggy artifacts and preserving fine details. Experimental results on real images captured using a prototype camera equipped with a coded electronic shutter show that our method can generate higher quality HDR images than previous approaches.