Abstract: Aiming at the two contrary viewpoints about the effects of mutual coupling on spatial correlation, two mutual coupling compensation techniques are employed to derive the channel capacity of multi-antenna system. Based on the electromagnetic numeric method and Monte Carlo method, it is pointed out that the effects of mutual coupling are also determined by the spatial channel parameters under the ray tracing model. As the mean angle of arrival varying, the effects of the mutual coupling will change from a detrimental factor to the beneficial ones. The equivalency of these two viewpoints is illuminated by the numeric results under Kronecker channel model.