This　paper　numerically　investigated　the　combustion　process　in　a　spark-ignited　(SI)　engine　fueled　with　hydrogen-gasoline　blends　through　the　computational　fluid　dynamics　(CFD)　calculation.　Satisfying　agreement　between　the　calculated　and　measured　in-cylinder　pressure　traces　was　observed　for　all　test　cases.　The　calculation　results　demonstrated　that,　the　hydrogen　addition　availed　the　increased　flame　propagation　speed　and　the　enhanced　degree　of　flame　wrinkling.　Compared　with　the　original　engine,　the　peak　flame　propagation　speed　was　raised　by　37.18%　and　60.47%　at　the　hydrogen　volume　fractions　of　3%　and　6%,　respectively.　The　peak　average　flame　surface　densities　of　the　3%　and　6%　hydrogen-enriched　engines　were　28.88%　and　35.99%　higher　than　that　of　the　original　engine,　respectively.　Copyright　(C)　2013,　Hydrogen　Energy　Publications,　LLC.　Published　by　Elsevier　Ltd.　All　rights　reserved.