The present invention describes a lighting device. The lighting device includes a first light guiding pillar, at least one first point-form light source, a second light guiding pillar and at least one second point-form light source. The first point-form light source is disposed near at least one end of the first light guiding pillar. The first and the second light guiding pillars are parallel with each other and integrally formed in one piece. The second point-form light source is disposed near at least one end of the second light guiding pillar. The first and the second light guiding pillars are integrated into a connection body having two opposite surfaces respectively forming two straight grooves on an intersection of the first and the second light guiding pillars, wherein two bottoms of the straight grooves are spaced by a predetermined distance.