The invention discloses an LED chip structure capable of improving light extraction efficiency. The LED chip structure comprises a substrate, an N-GaN layer, an active layer, a P-GaN layer, a low-refractive-index filler, a P electrode and an N electrode, wherein the N-GaN layer, the active layer and the P-GaN layer are formed on the substrate in sequence; the active layer and the P-GaN layer are etched to form a stage channel to expose a part of the N-GaN layer; the stage channel is filled with the low-refractive-index filler; the exposed part of the N-GaN layer is connected with the N electrode; and a P type layer is connected with the P electrode. By adoption of the LED chip structure, the forward direction extraction efficiency of side direction light of the LED chip is greatly improved, and the forward direction light intensity of the LED chip is enhanced.