The　combustion　and　emissions　characteristics　of　a　hydrogen-blended　gasoline　engine　under　idle　and　cylinder　cutoff　conditions　were　investigated　in　this　paper.　The　cylinder　cutoff　strategy　was　tried　with　the　engine　running　under　four　cylinder,　three-cylinder　and　two-cylinder　working　modes.　For　each　cylinder　closure　strategy,　hydrogen　energy　fraction　in　the　total　fuel　was　increased　through　increasing　hydrogen　injection　duration.　Meanwhile,　the　gasoline　flow　rate　was　reduced　to　ensure　the　hydrogen-gasoline　blends　in　the　working　cylinders　were　kept　at　the　stoichiometric　condition.　The　experimental　results　demonstrated　that　both　the　coefficients　of　variation　in　engine　idle　speed　and　indicated　mean　effective　pressure　were　reduced　after　the　cylinder　cutoff　and　hydrogen　addition.　Engine　indicated　thermal　efficiency　and　the　degree　of　constant　volume　combustion　were　improved　while　fuel　energy　flow　rate　was　reduced　with　the　increase　of　hydrogen　blending　fraction　and　the　number　of　closed　cylinders.　When　hydrogen　energy　fraction　in　the　total　fuel　reached　20.6%　at　the　two-cylinder　cutoff　mode,　fuel　energy　flow　rate　was　decreased　by　41%,　compared　with　that　of　the　original　engine　at　idle　and　stoichiometric　conditions.　Moreover,　hydrogen　addition　and　cylinder　closure　were　effective　on　reducing　engine　HC　and　CO,　except　for　NOx　emissions　at　idle　and　stoichiometric　conditions.　Copyright　©　(2014)　by　the　Committee　of　WHEC2014　All　rights　reserved.