A watermark and a manufacturing method therefor are provided. The watermark has a first region comprising amplitude modulation (AM) halftone dots and a second region comprising frequency modulation (FM) halftone dots, and each of the amplitude modulation halftone dots has ink portions and blank portions, each of which is located between the two ink portions in the same amplitude modulation halftone dot. The ink area percentage of the amplitude modulation halftone dots are dispersed by filling the blank portions into each of the amplitude modulation halftone dots, so that the density calibration of the amplitude modulation halftone dots and frequency modulation halftone dots can be omitted.