Cherenkov-type　terahertz　electromagnetic　radiation　is　revealed,　which　results　efficiently　from　the　collective　effects　in　the　time-domain　of　ultrafast　pulsed　electron　current　produced　by　ultrafast　intense　laser　plasma　interaction.　The　emitted　pulse　waveform　and　spectrum,　and　the　dependence　of　laser　pulse　parameters　on　the　structure　of　the　radiation　field　are　investigated　numerically.　The　condition　of　THz　radiation　generation　in　this　regime　and　Cherenkov　geometry　of　the　radiation　field　are　studied　analytically.