A heat-dissipating structure for an LED lamp has a lamp cover, and a power conversion device and a ceramic substrate mounted inside the lamp cover. The lamp cover has multiple heat-dissipating holes and multiple mounting ears. Each mounting ear is formed on an edge of one of the heat-dissipating holes and is bent inwardly with the heat-dissipating hole uncovered. The ceramic substrate is mounted on the mounting ears. The ceramic substrate has multiple LEDs mounted thereon, absorbs heat generated when the LEDs emit light and conducts the heat to the lamp cover through the mounting ears. The heat generated when the LEDs are lit and the power conversion converts a mains power is transferred to a heat convection space between the ceramic substrate and the lamp cover, and is further dissipated to an ambient environment, thereby achieving fast heat dissipation and a light LED lamp without an additional heat sink thereon.