A coolant heating apparatus for an electric vehicle includes a sheath heater formed in a coil form at a center side of the coolant heating apparatus; one or more inner tubes, one of which has an inlet formed at one side thereof for introduction of coolant, the one or more inner tubes being arranged to surround the sheath heater or to be surrounded by the sheath heater, and the one or more inner tubes having a plurality of through-holes formed on respective outer peripheral surfaces thereof so that the coolant introduced into the inlet is discharged through the through-holes; and an outer tube surrounding the sheath heater and the one or more inner tubes and having an outlet formed at one side thereof so that the coolant heated by the sheath heater is introduced through the through-holes of the one or more inner tubes and is discharged through the outlet.