Abstract: Benchmarking the critical experiments of nuclear assembly is a prerequisite for enriching the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Firstly, the core configurations and critical experiments of the SORA (Sorgente Rapida Reactor) mockup were introduced. Then the uncertainties of experimental k_eff for fifteen typical critical experiments were evaluated, resulting in the range of 0.002 3-0.002 7, and the biases with their uncertainties for modelization of the experiments were analyzed. Lastly the benchmarking results of k_eff with uncertainties were achieved. The results of numerical calculation of the SORA model are a little less than the benchmarking results of experiments in which the most relative deviation is less than 1%. The results meet the requirements for the inclusion of the International Handbook of Evaluated Criticality Safety Benchmark Experiments.