Modular seismic-resistant supporting system for constructions comprising: - at least one pair of outer vertical support elements; - at least one upper horizontal guide element and at least one lower horizontal guide element extending beyond the outer vertical support elements; - at least one pair of inner vertical support elements comprised between the outer vertical support elements, equipped with upper ends housed within said upper horizontal guide element and lower ends housed within said lower horizontal guide member; - at least one pair of transverse elements horizontally interconnecting the outer vertical support elements with the inner vertical support elements; - at least two pairs of squared contact regions, each positioned at the corner between each of said outer vertical support elements and each of said upper and lower horizontal guide elements (102a, 102b); and - at least one pair of retaining elements positioned above the transverse elements between each of the outer vertical support elements and the adjacent inner vertical support element; and at least one pair of diagonal elements connecting two squared contact regions diagonally positioned; characterized in that: - the at least one pair of retaining elements comprises an upper profile and a lower profile, the upper profile being overlaid to the lower profile; and - the upper and lower guide elements (102a, 102b) comprise a plurality of upper reinforcement elements inserted under the upper guide element between the outer vertical support elements and the upper ends of the adjacent inner vertical support elements and a plurality of lower reinforcement elements inserted above the lower guide element between the outer vertical support elements and lower ends of the adjacent inner vertical support elements. - at least one pair of outer vertical support elements; - at least one upper horizontal guide element and at least one lower horizontal guide element extending beyond the outer vertical support elements; - at least one pair of inner vertical support elements comprised between the outer vertical support elements, equipped with upper ends housed within said upper horizontal guide element and lower ends housed within said lower horizontal guide member; - at least one pair of transverse elements horizontally interconnecting the outer vertical support elements with the inner vertical support elements; - at least two pairs of squared contact regions, each positioned at the corner between each of said outer vertical support elements and each of said upper and lower horizontal guide elements (102a, 102b); and - at least one pair of retaining elements positioned above the transverse elements between each of the outer vertical support elements and the adjacent inner vertical support element; and at least one pair of diagonal elements connecting two squared contact regions diagonally positioned; - the at least one pair of retaining elements comprises an upper profile and a lower profile, the upper profile being overlaid to the lower profile; and - the upper and lower guide elements (102a, 102b) comprise a plurality of upper reinforcement elements inserted under the upper guide element between the outer vertical support elements and the upper ends of the adjacent inner vertical support elements and a plurality of lower reinforcement elements inserted above the lower guide element between the outer vertical support elements and lower ends of the adjacent inner vertical support elements.