Hydrogen　(H2)　and　ammonia　(NH3)　are　ideal　carbon-free　fuels,　and　the　application　of　NH3/H2　in　internal　combustion　engines　offers　the　potential　to　reduce　carbon　emissions.　And　turbulent　jet　ignition　(TJI)　is　an　advanced　ignition　strategy　that　can　effectively　enhance　the　combustion.　This　work　aims　to　experimentally　investigate　the　effect　of　NH3　addition　on　the　combustion　characteristics　of　H2/air　mixtures　under　passive　TJI　conditions.　Combustion　images　and　instantaneous　pressure　were　collected　for　processing　and　analysis.　The　effect　of　NH3　substitution　and　equivalence　ratio　were　investigated.　The　results　indicate　that　the　peak　combustion　pressure　decreases　with　the　addition　of　NH3,　accompanied　by　longer　combustion　duration　and　ignition　delay,　as　well　as　lower　jet　velocity　and　flame　area　growth　rate.　The　hot　jet　will　be　quenched　by　the　strong　heat　transfer,　causing　the　change　in　the　ignition　mechanism　as　the　NH3　substitution　ratio　increases.　In　addition,　compared　to　lean　conditions,　the　combustion　appears　to　be　less　sensitive　to　the　equivalence　ratio　on　the　rich　side　and　always　shows　high　jet　velocity　and　flame　propagation　speed.　However,　a　relatively　small　amount　of　NH3　addition　changes　the　ignition　mechanism　on　the　rich　combustion　side　compared　with　lean　conditions,　resulting　in　a　longer　ignition　delay.