A disc clamp mechanism for preventing a disc (e.g., DVD-ROM or CD-ROM) from slipping and/or loosening in a high speed rotation comprises a positioning member sized to the center hole of the disc having a hole for being mounted on a turntable, and an inclined surface; a helical spring within the positioning member; a disc-clamping member sized to the center hole of the compact disc having circumferential raised portions, recessed portions each extending from the raised portion, and flexible V-shaped members surrounded by two recessed portions and a raised portion; and an elastic plane-like member mounted on the positioning member. As such, the disc is secured by the raised portions, the inclined surface, and the turntable when loaded onto the disc-clamping member. This mechanism finds applications in the DVD-ROM or CD-ROM products. Further, a thinner construction, an easy assembly, and a high positioning precision are realized by this mechanism.