An LED vehicle headlamp includes an LED light source, at least one electrochromic device optically coupled to the LED light source, and a collimator positioned between the LED light source and the electrochromic device. The electrochromic device has an alterable light transmission characteristics in response to voltage/current level applied thereto. The collimator is configured for collimating and converging light emitted from the LED light source and directing light into the electrochromic device. When a forward bias voltage/current is applied to the electrochromic device, the visible light transmission of the electrochromic device decreases accordingly to generate a first light intensity distribution pattern, which is a low beam. When a backward bias voltage/current is applied to the electrochromic device, the visible light transmission of the electrochromic increases accordingly to generate a second light intensity distribution pattern (high beam) different from the first light intensity distribution pattern.