A light emitting diode (LED) lamp structure fixed to a mount and capable of emitting light for illumination includes a substrate, a light emitting element, a lamp cup and a joint member, and the light emitting element is installed on the substrate and has an LED lamp, and the lamp cup is mounted on the substrate and covered onto the light emitting element, and both joint member and mount have a joint portion, and one of the joint portions is concave and the other one is convex, and the concave joint portion has a diameter difference to define a large end and small end, and the convex portion is plugged from the large end of the concave joint portion, rotated with the joint member to move to the small end, and then fixed to the mount of the joint member.