Photocurrent spectrum of GaAs/AlGaAs superlattice at T=77K was measured.A strong photocurrent peak at ν=1589cm-1 and several weak peaks at ν=1779,2129 and 2401cm-1 were observed.It was believed that these photocurrent peaks are relevant to waving of electron in superlattice.The calculated positions of peaks of photocurrent on the basis of the theory of electron waving are in good agreement with experimental results.