The present invention provides a method for adjusting white-balance, comprising the steps of: S1, entering a value of white-balance of a standard sample into a display panel; S2, controlling the display panel to display a test image having different grayscale value so as to attain a full grayscale value of the display panel; S3, determining whether the attained full grayscale value is within a specification, if yes, then proceeding into next step, and if no, then proceeding into step S4; and S4, recalculating the white-balance value based on a difference between the attained full grayscale value and the white-balance value of the standard sample, and reentering the calculated white-balance value into display panel, and returning to step S2. The white balance adjusting system incorporated with such white balance adjusting method can be readily and quickly implemented into the existing production line of liquid crystal display panel.