Based　on　the　fact　that　the　polylactic　acid　(PLA)　has　high　crystallinity　and　poor　hydrophilicity　and　its　degradation　products　are　known　to　induce　inflammatory　reactions,　tyrosine　could　be　introduced　in　the　chain　of　polylactic　acid　to　enhance　its　poperties.　The　new　copolymers　poly(lactic　acid-co-L-tyrosine)　(PLA-co-Tyr)　were　synthesized　via　direct　melt　polycondensation　with　lactic　acid　(D,　L-LA)　and　L-tyrosine　(Tyr)　as　raw　materials　and　SnCl2　as　catalyst,　using　the　linear　heating　method.　The　copolymers　were　characterized　by　viscosity-average　molecular　weight,　FT-IR,　H-1-NMR,　GPC,　DSC,　and　XRD.　The　degradation　experiment　of　PLA-co-Tyr　was　carried　out　in　phosphate　buffer　solution　(PBS)　at　37　degrees　C　using　PLA　as　the　control　sample.　Scanning　electronic　microscopy　(SEM)　was　used　to　analyze　the　results　of　degradation.　The　results　demonstrate　that　with　reaction　conditions　of　170　degrees　C　and　500　Pa　and　with　0.4　wt.%　SnCl2,　10　h　of　polymerization　gave　the　PLA-co-Tyr　with　the　largest　average　molecular　weight　of　2900　g/mol,　which　appears　to　meet　the　requirements　necessary　for　a　drug　delivery　applications.　Compared　with　PLA,　it　has　lower　T-g　and　lower　crystallinity.　The　copolymer　has　good　thermal　stability　and　superior　performance　against　degradation.