Supramolecular hydrogels self-assembled by alpha-cyclodextrin and methoxypolyethylene glycol - poly(caprolactone)(dodecanedioic acid)-poly(caprolactone)-methoxypolyethylene glycol (MPEG-PCL-MPEG) triblock polymers were prepared and characterized in vitro and in vivo. The sustained release of dextran-fluorescein isothiocyanate (FITC) from the hydrogels lasted for more than I month, which indicated that the hydrogels were promising for controlled drug delivery. ECV304 cells and marrow mesenchymal stem cells (MSC) were encapsulated and cultured in the hydrogels, during which the morphologies of the cells could be kept. The in vitro cell viability studies and the in vivo histological studies demonstrated that the hydrogels were non-cytotoxic and biocompatible, which indicated that the hydrogels prepared were promising candidates as injectable scaffolds for tissue engineering applications.