Enzymatic　hydrolysis　lignin　grafted　glycine　(EHL-g-Gly)　copolymers　were　prepared　by　Mannich　reaction　with　enzymatic　hydrolysis　lignin,　glycine　and　formaldehyde　as　raw　materials.　The　effects　of　reaction　temperature　and　time,　the　dosage　of　formaldehyde　on　yield　and　graft　rate　were　investigated.　The　EHL-g-Gly　grafted　copolymers　were　characterizated　by　FT-IR,　TGA,　and　elemental　analysis.　The　results　show　that　the　reaction　temperature　and　time,　dosage　of　formaldehyde　have　great　influences　on　the　yield　and　grafting　rate.　The　most　high　graft　ratio　of　25.6%　is　achieved　at　the　reaction　temperature　of　90°C　for　3　h　with　the　mass　ratio　of　glycine　to　EHL　of　1:1,　the　molar　ratio　of　formaldehyde　to　glycine　of　2:1.　The　TGA　results　show　that　the　carbon　residue　of　EHL-g-Gly　significantly　increases　(7.0%)　than　unmodified　EHL.　The　nitrogen　content　of　resultant　EHL-g-Gly　has　obvious　increase　confirmed　by　elemental　analysis.