Abstract: In this paper, the directional characteristics of two different placed dual circular arrays are studied, including the direction of radiation pattern, the beam width of the main lobe and the sidelobe level. Firstly, the array model of the dual circular array is established, the formula of the radiation pattern is deduced and extended to multi-circle circular array, and theoretical analysis is carried out. Secondly, a large number of simulation experiments are carried out by MATLAB software to analyze the relationship among the half-power beamwidth of the main lobe, the sidelobe peak level, the scanning angle and the number of array elements, as well as the relationship between the radius of the inner and outer elements. Finally, the theoretical analysis and simulation results are comprehensively sorted out. The conclusions are that the lowest level of the sidelobe exists when the radius ratio of inner and outer array is about 0.5, and the beamwidth increases with the number of inner circular array elements but decreases with the number of outer circular array elements. The experimental results can provide theoretical reference for the reasonable setting of the number of elements and the location of the array elements.