In a method for calibrating marking in a laser marking system including a laser marker performing marking while observing chips contained in cells of a tray using a plurality of vision cameras, and a post-vision camera detecting a marking error (a) each chip is assigned to be observed to a corresponding vision camera, (b) a coordinate of the vision camera and a coordinate of the laser marker are matched, (c) a predetermined first symbol is marked on a chip or at a position corresponding vision camera, and one point of the first symbol is taught as a reference point, (d) the first symbol and the reference point of the chip are observed using the corresponding vision camera and a second symbol is marked on the chip with respect to the reference point, (e) the second symbol on a selected chip is observed and one point of the second symbol is taught as a comparison point, and (f) a position of the comparison point is detected from the reference point on the chip and the marking error in each cell is calculated.