A new design called spatial media-based modulation with multi-dimensional spatial constellation (SMBM-SC), which develops multiple index domains such as the channel index (CI), antenna index (AI) and key index for improving the spectral efficiency (SE), is proposed to construct the alpha-dimensional (alpha-D) complex spatial symbols to be transmitted over the specified channel states on the active antennas whose each with nrf mirrors. Specifically, with the control of alpha Switches, the alpha-D complex spatial symbol is generated by the alpha-D signal symbol. Then, with the aid of the specified AI vector with the AI bits, one Switch Controller feeds alpha components of the generated spatial symbol into alpha active antennas. Another Switch Controller feeds the CI information into alpha CI Vector Selectors and then modulate alpha components on the specified channel states with the CI bits to be transmitted, respectively. In addition, in order to further improve the SE, (alpha+1)-D spatial symbol is designed for exploiting the component permutation index by combining two types of signal symbols. The SE, the detection complexity and the average bit error probability (BEP) are analyzed. Simulation results demonstrate that the SMBM-SC enhance the reliability of communications as compared with the existing MBM schemes.