An LED lamp system with different color temperatures and various operation modes can resolve the problems occurred in the prior arts. By switching the AC current continuously, not only the LED lamp sets can emit lights of different color temperatures, and moreover, at the same time, the light sensitive detector and moving object detection circuit serve to detect environmental light intensity and the moving objects so as to auto-control the lighting and light intensity of the LED lamp sets so as to match the requirements of environment protection and power saving As a result, intellectual light control for LED lamps is achieved. This is beneficial to the applications of LED lamps.