Abstract: The cell pitch, 235U enrichment and burnable poison of annular fuel assembly were studied using CASMO5/SIMULATE5. The 1000 MWe reactor core pattern with annular fuel assembly was preliminary designed. Two types of fuel management strategies of the equilibrium cycle with 72 and 81 fresh assemblies were proposed, and the main physical parameters of the reactor were calculated. The results show that these parameters of 81 fresh assembly case including the cycle length, assembly discharge burnup, nuclear enthalpy rise factor, hot spot factor, moderator temperature coefficient, and shutdown margin meet the design criteria.