A driving system for hybrid electric vehicles includes a DC/DC converter configured to convert low-voltage DC power of a vehicle battery into high-voltage DC power according to a first PWM signal generated based on a first PWM carrier signal; a first inverter configured to convert the high-voltage DC power into first AC power according to a second signal generated based on a second PWM carrier signal, and drive a first driving motor according to the first AC power; a second inverter configured to convert the high-voltage DC power into second AC power according to a third PWM signal generated based on a third PWM carrier signal, and drive a second driving motor according to the second AC power; and a PWM phase controller configured to separately control phases of the first to third PWM carrier signals according to an operation mode of each of the first and second driving motors.