We herein report the discovery of a naturally derived carbohydrate with binding affinities for two pro-angiogenic growth factors-fibroblast growth factor-2 (FGF-2) and platelet-derived growth factor-BB (PDGF-BB). This galacturonic acid-containing polysaccharide (EUP3) sequestered endogenous FGF-2 and PDGF-BB in vivo and promoted in situ formation and maturation of new blood vessels. Our findings suggest EUP3 as the first nonglycosaminoglycan, nonanimal-originated carbohydrate molecule that binds two pro-angiogenic growth factors to stimulate angiogenesis. Further investigations into this carbohydrate may lead to the development of new tools for therapeutic angiogenesis.