Ulcerative　colitis　(UC)　is　an　idiopathic　intestinal　disease　with　an　increasing　incidence,　and　all　the　therapeutic　drugs　have　different　degrees　of　side　effects.　Studies　have　found　that　collagen　peptide　can　relieve　the　symptoms　of　UC,　and　is　safe　and　healthy.　However,　the　current　research　is　mainly　limited　to　the　prevention　effect　of　UC,　and　there　is　still　a　lack　of　research　on　the　therapeutic　effect　of　UC.　Eel　skin　is　rich　in　collagen,　but　eel　head　is　generally　discarded　in　processing,　resulting　in　a　waste　of　resources.　Meanwhile,　there　is　a　lack　of　research　on　eel　skin　collogen　hydrolysates.　In　this　study,　collagen　was　extracted　from　eel　skin　and　hydrolyzed　in　the　hope　of　obtaining　eel　skin　collagen　hydrolysate　(CH)　with　therapeutic　effect　on　UC,　so　as　to　improve　the　utilization　value　of　eel　processing　by-products.　It　was　found　that　eel　skin　contained　abundant　collagen,　accounting　for　27.87%　of　the　wet　weight　of　the　skin.　The　extracted　collagen　was　of　high　purity　and　mainly　type　I　collagen,　and　eel　skin　could　be　used　as　a　high　-　quality　source　of　collagen.　Collagen　was　enzymatically　hydrolyzed　to　obtain　eel　skin　collagen　hydrolysate　(CH)　with　antioxidant　activity,　and　CH　was　administered　to　DSS　induced　UC　mouse　model.　The　results　showed　that　CH　could　safely　and　healthily　reduce　DAI　score　to　0　and　improve　colon　status　in　UC　Model　mice　compared　with　Positive　control　group　and　Model　group.　Pathological　sections　of　colon　tissue　showed　that　CH　could　restore　the　integrity　of　mucosal　epithelium　and　reduce　inflammatory　cell　infiltration.　Oxidative　stress　index　of　colon　tissue　showed　that　CH　could　reduce　MDA　content　(0.75　nmol/mg　protein)　and　MPO　activity　(0.11　U/g　tissue)　in　colon　tissue,　and　improve　the　antioxidant　capacity　of　colon　tissue　and　reduce　oxidative　stress　level　by　increasing　GSH　content　(22.92　umol/g　pro)　and　activities　of　SOD　(693.61　U/g　pro),　CAT　(1.69　U/g　pro)　and　GPx　(141.29　U/g　pro)　antioxidant　enzymes,　so　as　to　treat　UC.　©　2023　Chinese　Institute　of　Food　Science　and　Technology.　All　rights　reserved.