A display device, and an optical compensation system and an optical compensation method thereof. A display device including a display panel including pixels; and a display driving circuit for driving the display panel and including: a storage unit for storing defect pixel information indicating which of the pixels are detected as defect pixels based on a brightness trend line of the pixels, and for storing compensation parameters regarding the defect pixels; and a brightness compensation unit for converting image data corresponding to the defect pixels according to the defect pixel information and the compensation parameters.