Abstract: The annular fuel assembly was designed and optimized using three-dimensional neutronic/thermal-hydraulics coupling code. Based on this assembly, the core design was also carried out. In the annular fuel assembly, the feed water flows through the center hole and periphery of the fuel. This brings both internal and external cooling for the fuel. Because of this character, a low fuel and cladding temperature can be reached with relative high power density. The water in the center hole also provides sufficient and uniform moderation for each pin, which is benefit for the local power distribution. DRAGON was used for assembly calculation to get the macroscopic cross sections. These cross sections were made into interpolated table for core calculation. The core calculation was based on CITATION and auxiliary depletion code CTBurn. The thermal calculation based on single channel model was used to obtain water density distribution. The distribution was taken as feedback for neutronic calculation. The results show that SCWR with the annular fuel assembly is a promising concept.