To　study　the　immune　and　anti-inflammatory　activities　of　Lateolabrax　maculatus　immunomodulatory　peptides　(LIP),　the　preparation　conditions　of　LIP　were　optimized　by　single　factor　experiments　and　response　surface　methodology　with　the　stimulation　index　of　mouse　spleen　lymphocytes　as　an　indicator.　RAW264.　7　macrophage　model　was　used　to　study　the　immunomodulatory　effect　of　LIP,　and　anti-inflammatory　activity　of　LIP　was　explored　by　constructing　a　lipopolysaccharide-induced　RAW264.　7　macrophage　inflammatory　model.　The　results　showed　that　the　optimal　preparation　conditions　for　LIP　were　as　following:　solid-liquid　ratio　1.　0:　3.　8　(g　/　mL),　enzyme　adding　amount　2.　14%,　papain　hydrolysis　time　56　min.　Under　this　condition,　the　stimulation　index　of　mouse　spleen　lymphocytes　reached　2.　57.　The　results　of　macrophage　immunoactivity　show　that　LIP　exerted　immunomodulatory　activity.　400　μg　/　mL　LIP　exerted　immunomodulatory　effects　by　promoting　the　proliferation　and　phagocytosis　capacity,　nitric　oxide　and　reactive　oxygen　species　production,　nitric　oxide　synthase　(iNOS)　mRNA　expression,　and　proinflammatory　cytokines　secretion.　Moreover,　400　g　/　mL　LIP　also　showed　effectively　anti-inflammatory　capacity　by　downregulating　prostaglandin　E2　and　proinflammatory　cytokines,　and　reducing　excessive　secretion　of　NO　via　inhibiting　overexpression　of　iNOS　and　cyclooxygenase-2　mRNA.　These　results　suggested　that　LIP　exerted　bidirectional　immunomodulatory　activity,　including　“increasing　immune　response＂　and　“inhibiting　excessive　immune　response　＂,　which　provided　a　theoretical　basis　for　bidirectional　immunomodulatory　functional　foods　research.　©　2023　Beijing　Technology　and　Business　University,　Department　of　Science　and　Technology.　All　rights　reserved.