In this paper, channel capacities of indoor MIMO-UWB (multiple input multiple output-Ultra wideband) transmission for different material partitions are described. A ray-tracing technique is applied to compute the frequency responses for an environment with different material partitions. All the material parameters of our simulation environments such as dielectric constant and conductivity are both dependent on operating frequency in our calculations for UWB transmission. In other words, these material parameters are frequency selective for our calculation. By frequency responses of our simulation environment, channel capacities of MIMO-UWB transmission are calculated. Furthermore, outage probability is also computed for analyzing statistical property. Based on the calculations, the effects by different material partitions on 2X2 MIMO-UWB transmission are compared for different signal power to noise power ratio (SNR). In addition, the effects by different material partitions for different antenna array are investigated and compared to SISO (single input single output). Numerical results show that the Styrofoam partition has largest transmission rate, and the plywood partition has smallest one. Finally, it is worth noting that in these cases the present work provided not only comparative information but also quantitative information.