Disclosed is a battery module assembly, which includes four battery modules, each having a plurality of cylindrical secondary battery cells (hereinafter, also referred to as ‘cells’) interposed between an upper frame and a lower frame, wherein among the four battery modules, two battery modules are arranged in parallel, and two battery modules are stacked on the two battery modules arranged in parallel. Therefore, it is possible to provide a stable and economic battery module assembly including a plurality of secondary battery cells.