The improved Chinese pressurized reactor CPR1000 is one of the widely used second-generation pressurized water reactor in China. Quantitative verification of the Monte Carlo code in CPR1000 series reactors is a key step to demonstrate its ability in engineering design. Based on the actual parameters of a CPR1000 unit, the JMCT Monte Carlo code was used to perform particle transport modeling and calculations. Critical calculations and fixed-source calculations were performed, then the verification and validation were conducted. For critical calculations, a full core pin-by-pin model was established using JMCT to calculate the effective multiplication factor and power distribution of the core. For fixed source calculations, a reactor model for shielding analysis and a detailed structural model of irradiation surveillance capsules (ISC) were established. Based on the neutronic parameters of multiple refueling cycles, simulation was performed to calculate the cumulative fast neutron fluence for two ISC extracted from two nuclear power plants. By comparing the calculation of JMCT with the reference code and measurement, the simulation ability of JMCT code in CPR1000 reactor was demonstrated, and it was proven that the calculation accuracy of JMCT code is of engineering-level.