An LED package structure for increasing light-emitting efficiency includes a heat-dissipating unit, an insulating unit, a light-emitting unit and a conductive unit. The heat-dissipating unit has a heat-dissipating substrate. The insulating unit has an insulating layer formed on the heat-dissipating substrate and at least one receiving groove passing through the insulating layer and formed above the heat-dissipating substrate. The insulating layer has a top surface on a top side thereof and an inner surface, and the inner surface of the insulating layer is an annular inclined surface in the receiving groove. The light-emitting unit has at least one light-emitting element received in the receiving groove and disposed on the heat-dissipating substrate. The conductive unit has at least two conductive structures disposed on the insulating layer and separated from each other, and the light-emitting element has two electrodes respectively electrically connected to the two conductive structures via two conductive wires.