A simple and efficient method of the evaluation of MIMO channel capacity has been proposed. First, the channel capacity of a half wavelength dipole array antenna was calculated using a Monte Carlo method by changing incident wave SNR, power difference between two elements, and correlation coefficient. Using the calculated results, a polynomial function of estimating the channel capacity was given by the multivariate regression analysis. Effectiveness of the developed function was verified by comparing the channel capacity estimated by the developed function and that calculated by the Monte Carlo method using a MIMO array antenna mounted on a mobile terminal close to the human body. Finally, GUI software has been developed, so that simple and efficient calculation of the MIMO channel capacity can be performed without a large amount of computer and human resources.