could be bad spark plugs and/or plug wires if one or all is bad they will make the cylinders misfire and cause a bad vibration, also could be fuel related such as a dirty fuel filter, but i would check the plugs and wires first.
If it's a Diesel, it's meant to, otherwise, has it been serviced recently? Does it only do it when idling?
Might be idle control valve/ECU. probably best take it to a garage.