Photocurrent spectrum for GaAs/AlGaAs superlattice at T = 77 K was measured. A strong photocurrent peak at ■ = 1598 cm-1 in the photocurrent spectrum was observed. It;was believed that the strong photocurrent peak is relevant to electron reflection at interface in superlattice. On the basis of the point of view, calculated position of peak of photocurrent is in very good agreement with experiment result.