Non-activated tissue-regeneration polypeptides (TRPs) and their preparation methods are disclosed. The TRPs include: a protein transduction domain (PTD) making the polypeptides to permeate a cell membrane without cell membrane receptors; a furin activation domain (FAD) which has at least one proprotein convertase cleavage site and which can be cleaved by the proprotein convertase and activate a tissue regeneration domain (TRD) in cells; and a tissue regeneration domain (TRD) which can be activated by the proprotein convertase cleavage of the FAD to stimulate the growth or formation of tissues or to induce the regeneration of tissues. The TRPs can be mass-produced by cultured bacteria, such as recombinant E. coli, are in a non-activated state before in vivo administration, and their separation, purification, handling, storage and administration are simple and convenient. The in vivo administration of the TRPs is useful to stimulate the formation or regeneration of tissues, such as bones or cartilages, or to improve the fibrosis and cirrhosis of organs, such as kidneys, liver, lungs and heart by pharmacological mechanisms completely different from those of prior rhBMPs or TGF-β proteins.