A light emitting diode (LED) package structure includes a circuit board, a reflective cup, a LED chip and a lens structure. The reflective cup is mounted on the circuit board, wherein the reflective cup and the circuit board collectively form a concave cup with an opening. The reflective cup has a first metal ring in the concave cup. The LED chip is mounted on the circuit board and within the concave cup. The lens structure has a second metal ring configured to join the first metal ring to cover the opening.