Abstract: The subcritical energy reactor (SER) is a fusion-fission hybrid reactor which is driven by Tokamak fusion source. SER uses natural uranium and water coolant. Its main object is to produce power. SER models with annulus cylinder were established. With Monte-Carlo transport and burnup codes, models with different fuel zone configurations were compared, then neutron source efficiency and fusion neutron source rate, power distribution and neutron spectrum, primary burnup, decay heat at the ending of life (EOL) and radioactivity of discharged fuel were calculated. The results show that the models can meet the design objects, that energy multiplication factor is bigger than 6, tritium is self-sufficient, the fuels are reloaded in a long time, and so on. The results provide the basis of SER safety analysis which will be done in the future.