Terahertz radiation is an electromagnetic radiation, which frequency spectrum situated between microwave and infrared waves (0.1-10 THz). Terahertz radiation is a perspective for using in imaging and spectroscopic applications[1], [2]. Simple method to generate terahertz radiation is a photoconductive antenna. Basis of the terahertz antenna is a semiconductor thin film, which have such properties as low carrier lifetime, high carrier mobility and high resistivity. The recent achievements in modification of the most popular semiconductor material – InGaAs show, that creation of the superlattices InGaAs/InAlAs is an effective method to enhance resistivity and minimaze the dark current [3].  In this work the terahertz generation from InGaAs/InAlAs superlattice was measured by time domain terahertz spectroscopy. As shown at previous works [4] the maximum of the generated terahertz amplitude was at higher optical excitation photon energy. Due to previous work, terahertz generation was obtained at wavelength of optical excitation from 800 – 1000 nm. The results show good agreement with theoretical work and the spectrum of generated terahertz radiation as well the amplitude increased with injected photon energy. The widest spectrum of generated terahertz radiation and maximum of the amplitude was observed at optical wavelength 825 nm.