A modular building structure with relative integrated plants, as obtained by assembling a plurality of module frames to obtain a complex frame, allows associating ducts of one or more plants to the module frame. The module frames have a parallelepiped-like shape and are identified by beams joining in respective angles, including a plurality of connecting knots joining module frames adjacent to the angles; the adjacent beams of side-by-side module frames are spaced apart by the knots and the panels and are connected to the beams of the module frame thereto, so as to create an air gap. The integrated plants have a plurality of ducts arranged in the air gaps and in the through channels, which include, at edges or angles of the module frame, quick connections for connecting the ducts related to a module frame to those of another module frame placed side-by-side thereto.