Abstract: For the aqueous luminol solution, three absorption bands with maximum. adsorption wavelength λ_max 220.7、294.4 and 351.5nm respectively have been detected, with the exception of a little hyperchromic effect, the absorption spectrum contour of the solution cavitated by an ultrasound with a frequency of 1.45 MHz has been certificated to be unchanged. The absorption spectra of the aqueous luminol-NaOH solution and its cavitated solution are similar to the that of the aqueous luminol solution, only the cavitated solution appearing a bit of hyper-and hypo-chromic effects.For increasing the concentration of Cu²⁺ to 1.8×10^-4mol/l, the difference in some degree exists in luminol-NaOH-Cu²⁺ solution and its cavitated solution, that is the absorption degree of the cavitated solution rising up apparently between 220~350nm, however, the absorption spectrum contour of the solution are still similar to the that of the aqueous luminol solution.