The present invention relates to a fusion protein comprising an LRG1 glycoprotein and a composition for preventing or treating impotence, ischemic diseases or peripheral nerve diseases, containing the same as an active ingredient. The LRG1 glycoprotein or an LRG1-Fc fusion protein according to the present invention increases the level of endothelial cell-specific and nerve cell-specific proteins, and thus has an excellent effect of improving impotence such as inducing the regeneration of the endothelial cells and nerve cells of the corpus cavernosum and increasing penile erection, thereby being usefully used for the prevention or treatment of impotence. Further, the LRG1 glycoprotein or LRG1-Fc fusion protein according to the present invention has the effect of regenerating blood vessels and nerves, and thus can be usefully used for the prevention or treatment of ischemic diseases or peripheral nerve diseases.