Objective:　The　study　aimed　to　explore　the　antioxidant　activity　and　stability　of　Lateolabrax　maculatus　protein　hydrolysates　(LPH)　in　vitro.　Methods:　Chemical　experiments　were　used　to　determine　the　antioxidant　activity　of　LPH　and　analyze　the　effects　of　pH,　temperature,　metal　ions　(K+,　Ca2+,　Cu2+,　Zn2+)　and　simulated　gastrointestinal　digestion　on　its　stability.　And　the　oxidative　damage　model　of　Caco-2　cells　induced　by　hydrogen　peroxide　was　used　to　explore　the　protective　effect　of　LPH　against　cellular　oxidative　damage.　Results:　LPH　had　strong　free　radical　scavenging　activity　against　DPPH　and　ABTS　and　the　IC50　values　were　2.13　mg/mL　and　31.53　μg/mL　respectively.　LPH　was　stable　to　pH(2.0~12.0),　temperature　(25~100　℃)　and　K+　(0.25~2　mmol/L).　Ca2+　and　Cu2+　at　0.25~2　mmol/L　improved　DPPH　scavenging　rate　of　LPH,　while　Zn2+　above　1　mmol/L　decreased　it.　In　addition,　LPH　had　good　gastrointestinal　stability.　In　the　Caco-2　cell　model　induced　by　hydrogen　peroxide,　LPH　significantly　increased　cell　viability　from　58.02%　to　83.40%　(P<0.05),　significantly　inhibited　the　release　of　intracellular　reactive　oxygen　species　(P<0.05)　and　restored　mitochondrial　membrane　potential　to　normal　level.　Furthermore,　LPH　significantly　inhibited　the　activity　of　lactate　dehydrogenase　in　supernatant　to　19.34%　of　model　group　(P<0.05)　and　significantly　increased　the　activities　of　superoxide　dismutase　and　catalase　in　cells　(P<0.05).　Conclusion:　LPH　had　good　antioxidant　activity　and　stability,　suggesting　a　good　application　prospect　in　the　area　of　functional　nutritious　food.　©　2023,　Editorial　Department　of　Science　and　Technology　of　Food　Science.　All　rights　reserved.