The　Cherenkov　radiation　resulting　from　a　fast　electron　in　ultrashort　intense　laser　plasma　is　explored　theoretically　based　on　the　density　perturbation　theory.　The　radiation　emitting　conditions　and　characteristics　of　the　corresponding　Cherenkov　geometry　are　discussed　in　detail.　By　numerical　computation,　a　significant　conclusion　is　revealed　that　the　THz　radiation　of　Cherenkov-type　can　be　excited　by　the　coupling　of　a　fast　electron　produced　by　an　intense　ultrashort　pulse　laser　and　plasma　medium　in　specifically　parameter　conditions.　The　results　show　that　the　radiation　intensity　is　strongly　dependent　on　the　pulse　duration　of　incident　laser　and　the　velocity　of　a　fast　electron,　the　emission　spectrum　width　is　dependent　on　the　plasma　density　and　the　ratio　of　a　fast　electron　and　laser　group　velocities,　and　the　emission　angle　distribution　is　dependent　on　the　effective　radius　of　laser　beam.　(c)　2007　American　Institute　of　Physics.