This paper presents the design and implementation of LED street lamps with 60Hz ferroresonant transformer to achieve the high-frequency noise attenuation and AC line voltage regulation. The high-frequency transformer used in the LED driver system for the outdoor LED street lamps cannot effectively suppress the surge and inrush currents to avoid the damage on the LED street lamps. However, the low-frequency transformer can be applied to protect the LED street lamps from the surge and inrush currents instead of the high-frequency transformer. The turns numbers of the low-frequency transformer, which are much more than those of high-frequency transformers, provide larger leakage inductances and parasitic capacitances to effectively suppress and shunt the surge and inrush currents, respectively.