Two kinds of sensor structures for 3D direct capacitance imaging are presented. 12 electrodes are arranged in three planes each with four electrodes. Every four electrodes on each plane are rotated 45° (sensor 1) or 0° (sensor 2) with reference to the previous. A comparative study between the two sensors shows that although the difference in sensor’s sensitivities and outputs is obvious, the difference in reconstruction images isn’t apparent, at least for some permittivity distribution. The output range of sensor 1 is smaller than that of sensor 2, thus sensor 1 is better than sensor 2 in terms of the design of a capacitance measuring circuit. Both sensors can achieve 3D direct capacitance imaging with a good axial resolution.