In a LED lamp structure and an illuminating module thereof, the illuminating module includes a circuit board, a flat plate LED, an electrical pin and a packaging colloid. The circuit board has a length, a first and a second side formed at two sides of the length. The flat plate LED is fixed and electrically connected with the circuit board, bulges at the first side, and includes a substrate and at least one LED grain assembled on the substrate. The flat plate LED can emit omnidirectional light because the substrate is made of transparent material. The electrical pin is fixed and electrically connected with the circuit board and bulges at the second side. The packaging colloid covers the circuit board and the flat plate LED and has a rectangular plastic block. Thereby, the LED lamp structure can remain traditional appearance of a halogen lamp, for collecting and focusing light.