Geometrically based single-bounce elliptical model (GBSBEM) does not consider the impact of time delay and pitch angle, and cannot response the correlation between MIMO antennas. In order to solve these problems, an improved threedimensional MIMO channel model based on GBSBEM is presented. By introducing spatial distance and pitch angle, this model transformed the 2D GBSBEM to 3D GBSBEM, which includes space distance, direction of arrival (AOA) and multipath time delay. And the probability density functions of the AOA, time delay and their joint are also derived. What’s more, by building 3D GBSBEM between multi-antennas, 3D MIMO GBSBEM is presented. For illustration, MATLAB simulation is utilized to show the feasibility and applicability of this 3D MIMO GBSBEM. The analysis results show that the improved model is not only compatible with the original model, but also improve the accuracy of the latter, and extend the scope of its application. The improved model is more suitable for analyzing the signal reception performance of MIMO communication systems.