Compared the UV absorption spectra of some magnetized samples with them of unmagnetized samples(the pure solvents and unmagnetized solutions as the reference substances separately), we found the wavelength of absorption didn't change, but strength of absorption of all magnetized compounds changed. When unmagnetized solutions is selected as reference substances, there may be a peak of magnetic effect in UV absorption spectra. Furthermore, the different magnetization time made the absorbance change in varying degrees. This research will play an important role for the study of possible mechanism of magnetic field effect on chemical reaction.