Emergency　braking　event　of　the　vehicle　in　front　is　one　of　the　main　causes　of　a　forward　collision.　If　the　driver　can　sense　the　emergency　braking　event　of　the　vehicle　in　front　timely,　the　coping　behavior　can　be　changed　from　passive　visual　stimulation　to　active　coping　behavior　based　on　psychological　expectation,　which　will　greatly　reduce　the　accident　rate.　Based　on　driving　simulation　technology,　an　emergency　braking　event　in　the　cooperative　vehicle　infrastructure　system　was　designed　to　provide　the　emergency　braking　warning　information　of　the　vehicle　in　front　with　the　vehicle-mounted　Human　Machine　Interface　(HMI)　at　the　distance　of　360　m　and　290　m.　Driving　behavior　data　and　evaluation　indexes　were　obtained　from　driving　behaviors　of　qualified　drivers　in　the　driving　simulation　experi-ment.　After　a　comparative　analysis　of　driving　behavior　data　with　and　without　HMI　warning　information,　a　method　was　proposed　for　analyzing　the　driving　characteristics　of　the　emergency　braking　event　of　the　vehicle　in　front　in　the　cooperative　vehicle　infrastructure　system　based　on　spatiotemporal　diagram.　The　driving　confidence　characteristics　of　35　drivers　in　emergency　braking　event　were　analyzed　based　on　their　average　acceleration　characteristics.　The　results　show　that　when　the　HMI　warning　information　is　available,　the　drivers　tend　to　decelerate　earlier　with　lower　speed　control　intensity　than　that　when　the　HMI　warning　information　is　not　available.　According　to　the　curvature　index,　the　speed　control　intensity　is　reduced　by　39.4%.　When　the　HMI　warning　information　is　available,　the　speed　control　is　more　leisurely,　and　the　drivers　can　proactively　respond　to　the　risk　environment　with　the　characteristics　of　driving　confidence.　©　2020,　Editorial　Department,　Journal　of　South　China　University　of　Technology.　All　right　reserved.