A nose-rest mechanism for safety glasses includes a lens unit, a fixing device, and a nose piece. The nose piece includes two nose rests and a first extended section upward extended from between the two nose rests. The fixing device defines an inner receiving space adapted to receive and confine a middle bridge section of the lens unit and the first extended section of the nose piece thereto. The nose piece is provided on the first extended section with at least one projecting portion or at least one through hole for engaging with at least one retaining hole on the fixing device or at least one projecting section on the lens unit, respectively, enabling the nose piece to be easily, stably, and detachably connected to the lens unit via the fixing device while maintaining the safety glasses in a beautiful appearance.