Objective—To obtain a theory of verifying handwriting with reflectivity.Method— Make the hyper spectral curves and measure the reflectivity of some parts of every trademark.Next,determinant if the reflectivities are different prominently.Result —The reflectivity' distinguish is 85% at 680 nm wavelength of blue-point mark when believability is 95%.Conclusion —It is feasibility to verify handwriting with reflectivity and the conclusion of the optics will be used with the other methods.