An LED lamp tube comprises a tube body, at least one circuit board inside the tube body, at lease one LED module on the circuit board, and electrical connectors at the ends of the tube, wherein the tube body is an integrally formed hollow tube, and has at least one group of supporting and positioning ribs on the inner wall thereof along the length direction; the circuit board is fixed by the supporting and positioning ribs; the LED lamp tube disclosed by the present invention has a firm assembly structure with less thermal deformation, and more particularly just like the conventional fluorescent tubes it has a wide light-emitting angle, thereby providing better illumination effects.