||Injectable hydrogels have been much attention due to their wide applications in drug delivery and tissue engineering. In this study, a new injectable hydrogel was investigated with water-soluble 4-arm PEG-PDLA (4-PPD) and 4-arm PEG-PLLA (4-PPL) block copolymers using stereocomplexation between the PDLA and PLLA enantiomer blocks. 4-PPD and 4-PPL block copolymers were prepared by the stannous octoate catalyzed ring opening polymerization of D- or L-lactide initiated by hydroxyl groups of 4-arm PEG at 130 ℃ for 6 h. The chemical structures of 4-PPD and 4-PPL copolymers were characterized by 1H NMR, FT IR and DSC. Gel formation was studied by rheological experiments on the polymer solutions. This stereocomplexed hydrogel could be easily injected because of these enantiomeric components with relatively low viscosity and suitable mechanical property. Therefore, this hydrogel is expected to be utilized as an injectable scaffold for various tissue applications.