A cholic acid (CA)-containing biodegradable hydrogel (PLA-PEG-PLA-co-MACAH) was synthesized from the photoinduced copolymerization of a CA-modified methacrylate monomer (MACAH), bearing a spacer of hexane-1,6-diol spacer between the methacryloyl and the cholanoate moieties, and a macromonomer (PLA-PEG-PLA-DA), bearing two acryloyl end groups derived from a poly(lactic acid)-b-poly(ethylene glycol)-b-poly(lactic acid) triblock copolymer. The structure of MACAH was confirmed by FTIR, H-1-NMR, and MS. The hydrogel PLA-PEG-PLA-co-MACAH was characterized by scanning electron microscopy and X-ray diffraction. The experiment results showed that the swelling ratios of the hydrogels decreased with the increase of the CA fraction. The investigation on the in vitro degradation of the hydrogel showed that the CA-containing hydrogels; degraded much slower than the hydrogels without CA component. The bioactivity of the synthesized hydrogels was assessed by the simulated body fluid method. The observed formation of hydroxyapatite on the scaffold of the hydrogels indicated that the hydrogels possess good bioactivity. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 2976-2980, 2009