A method for controlling an engine clutch of an electrified vehicle is provided to easily engage and disengage an engine clutch by applying a launch engagement control method that utilizes power from both of an engine and a motor in accordance with the variation of the number of revolutions per hour of the engine and the usage rate of electrical energy by a motor to engage the engine clutch in a terrain mode and by applying a control method that disengages an engine clutch early in accordance with the number of revolutions per hour of the engine and the shaft torque of the engine clutch in the terrain mode.