Abstract: Using the critical experiment data of mocking up spent fuel high density storage of American B&W Company, critical experiment data of mocking up fuel assembly transportation basket ofPacific Northwest Laboratories (PNL), and critical experiment data from Shanghai Nuclear Institute, checking calculation of AMPX-KENO Monte Carlo program is performed. The errors of k.ff values are less than 2% for most schemes, less than 3% for very few schemes. Critical water level of Heavy Water Zero Power Reactor (HWZPR) is calculated by this program, and difference of keff values between the calculation and the measurement at initial criticality is less than 1%. Numerical calculation results show that AMPX-KENO program is applicable to the criticality calculation for rod lattice systems with the fuel of low-enriched or natural uranium,with moderator of light water or heavy water.