Photocurrent relaxation technique has been used to study the deep states in amorphous arsenicselenium films As_xSe_1-x with x=0.02, 0.05, 0.1, 0.28, 0.4, 0.45, 0.5 and 0.6 using monochromatic light pulse (λ,=0.63 μm, Φ=(1-3)·10¹⁴ (photon) cm ^-2s^-1 τ∼25 s) at room temperature. The i _ph x t vs. kTln(vt) diagrams are used to evaluate the density-of-state (DOS) distribution in analogy with time-of-flight (TOF) post-transit photocurrent analysis. For the composition of x=0.02 this distribution consist of a broad maximum located near 0.69 eV. As the concentration of arsenic increase the position of the maximum increase up to 0.84 eV at x=0.4 and it width also increase in this range of composition. On contrary, for x>0.4 the DOS function consist of the narrow peak extended in the mid-gap and it intensity abrupt falls for x=0.45 and 0.5. By comparison with the steady-state photocurrent spectra the relaxation of photocurrent for x<0.4 have been interpreted as due to deep acceptor-like centers associated with D⁺ and D^- defects with negative U^-. For x>0.4 such interpretations suggest the reductions in defect densities because stressed rigid phase.