In low-dimensional materials a large portion of atoms are placed at or near the surface with lower bond order and higher energy per atom. Thus, reduction of the surface energy and surface stresses drives surface relaxation and reconstruction and formation of new low-dimensional nanostructures, which can be utilized for tailoring the properties and phase transformation of nanomaterials without applying any external load. Furthermore, surface tension dominates for this class of materials which can inherently result in the extreme stresses that triggers structural changes. Here we used atomistic simulations and revealed an intrinsic structural transformation in monolayer materials that lowers their dimension from 2D nanosheets to 1D nanostructures to reduce their surface and elastic energies. Experimental evidence of such transformation has also been revealed for one of the predicted nanostructures. Such transformation plays an important role in bi-/multi-layer 2D materials.