Single-mode fiber-designed optical coherence tomography (OCT) system is developed and applied in ophthalmic imaging. Images with high signal-to-noise ratio, high resolution and large image depth, are achieved by the developed system. The calibrated axial resolution and transversal resolution are 9 μm and 10 μm, respectively, and the maximum depth range is 3.4 mm. Comparison between experimental results and Zeiss OCT Ⅲ are presented. The results show that the proposes OCT system can image not only the layers of retina , but also the layers and vas of choroid which cannot be obtained by Zeiss OCT Ⅲ.