A hinge for a notebook extension pad is mounted in an expansion pad of a notebook and has a pivoting assembly, a positioning disk, a limiting stationary leaf, a limiting disk, a pressing assembly and a locking assembly. The expansion pad has a mounting segment and a pad. The pivoting assembly is mounted securely on the pad and has a shaft. The positioning disk is mounted around the shaft. The limiting stationary leaf is adjacent to the positioning disk, is mounted rotatably around the shaft and connects with the mounting segment. The limiting disk limits movement of the pad relative to the mounting segment. The pressing assembly provides friction against movement to the hinge. The locking assembly is mounted around the shaft and selectively holds the pad at an angle allowing the pad to be used to display the notebook for presentations or achieving a comfortable typing angle.