An LED lighting device includes a light pipe and a support portion. The light pipe includes a light emitting diode module inside and two first fastening portions on an outer wall thereof. A support portion secures the light pipe and provides a rotatable function for the light pipe. The support portion further includes a clamp and a base member. A clamp has two second fastening portions at opposite sides thereof. The second fastening portions engage with the first fastening portions. The clamp further includes a strip hollow slot. A base member includes a pair of positioning portions for holding an outer wall of the clamp, wherein a fastener is led through the strip hollow slot and fastened on the base member. The clamp slides relative to the base member along the strip hollow slot such that the light pipe rotates relative to the base member.