A circuit board with a quality-indicator mark and a method for indicating quality of the circuit board. The circuit board includes a plurality of circuit board units. A plating bus is formed around each circuit board unit and extended to form a plating trace in an inner-layer circuit structure of each circuit board unit. The inner-layer circuit structure is inspected in quality to maintain or break connection between the plating trace and plating bus if the quality is good or not. At least one circuit structure is formed on the inner-layer circuit structure and electrically connected to the plating trace to form a conductive mark on each circuit board unit. A metal protection layer is formed on the at least one circuit structure via the plating bus, and the conductive mark with the metal protection layer indicates that the inner-layer circuit structure of the circuit board unit is good.