Abstract: Flow distribution investigation at core inlet is an important engineering validation experiment during the design process of a new type nuclear reactor. It can provide experimental data for thermal-hydraulics and safety analysis of nuclear reactor. A flow distribution characteristic experimental investigation at core inlet in China Engineering Test Reactor (CENTER) was carried out based on a scaled-down model. Flow distribution factors under different working conditions among simulating fuel assembly, beryllium/aluminum assembly, and cobalt target assembly and control rod guide tube simulators were obtained. Experiment results show that under the working conditions in this paper, large amount of coolant flows through simulating fuel assembly and the flow distribution factors among the same kind assemblies are homogeneous, and the max relative deviation is within ±4%. The total inlet flow in the experiment has little influence on flow distribution characteristic.