本文讨论了电化学交流阻抗图中图形旋转的物理意义. 电化学体系等效电路中的电容基本上属复数电容，由此推导出在这个假设下的阻抗极坐标公式，及其参数的数学表达式. 实际上此表达式与很多电化学体系的实际阻抗谱相符，如：实际测量的理想极化电极的阻抗图并不是平行于虚轴的一条直线，而是其与实轴的交点顺时钟旋转了α角的直线，这时α=arctgC"/C'，即双层电容的耗散角；与RC并联电路有关的半圆阻抗图几乎都有同一方向的α角旋转，其值等于相关电容的耗散角. 若明确了旋转的物理意义，由电化学阻抗谱拟合得到的参数均可表征体系的性质，这对于寻求某些特殊性能的电池体系将是有用的.

The essential of the rotation of complex impedance diagram in some electrochemical systems is discussed. It is attributing to that the electrochemical capacitance usual is not simple real capacitor but must be complex number capacitance. As the examples: 1, the metal/support electrolyte electrode in the ideal polarization condition, the capacitance must be that of the electrochemical double layer and represents complex number properties. Its complex impedance diagram was not a line parallel to imaginary axis but rotated clockwise α=arctgC"/C'. 2, In the case of insertion/desertion electrodes, the capacitance must be that of the solid electrolyte interphase (SEI). The rotation of impedance diagram also was attributing to the complex number properties of the capacitance of SEI membrane. The capacity and the rotation angle may be used to characterize the electric and the structure properties of the SEI.