The invention discloses a method and a system of adjusting chromaticity balance and quantization parameters. According to the method provided by the invention, an increment of the chromaticity quantization parameter is adjusted through prejudgment of a balance degree of brightness and chromaticity, so that the purpose of improving the brightness rate-distortion performance is achieved. In addition, a scene detection step is provided in the method in an embodiment of the invention, so that the prejudgment of the balance degree of the brightness and the chromaticity can be carried out duly, and the self-adaptive adjustment of the chromaticity quantization parameter is achieved. Finally, optimization between improvement of the brightness rate-distortion performance and control of a calculated amount is implemented.