Abstract: Optical coherence tomography (OCT) is a medical imaging technology that can perform high resolution, cross-sectional imaging of tissue morphology in situ and in real time, which is widely used in diagnosis of retinal diseases. Recently, the advances of OCT technology have enabled OCT imaging with increasingly speed and more axial resolution, which is called ultrahigh-resolution OCT. The outer retina was resolved several separate bands by the newer OCT and many studies focus on the changes of these bands in retinal diseases in recent years, which can help us understand outer retinal micromorphology more deeply. In addition,  enhanced depth imaging (EDI) technique can lead to increased visualization of the choriocapillaris anatomy in OCT image. This article reviews the research progress and clinic application of ultrahigh-resolution OCT in outer retinal micromorphology and choroidal imaging.