Photoconduction spectra as a function of temperature, electric field and additional illumination are studied in crystals of NbS3 (phase I). We observe the low-energy cut-off of photoconduction corresponding to the gap edge and electronic states within the gap. The states reveal themselves as peaks in photoconduction spectra; the amplitude of the peaks depends on the value of electric field applied, temperature and additional illumination. Two peaks at energies 0.6 eV and 0.9 eV and a tail of photoconduction at energies between 1 eV and 0.7 eV are observed. In addition, the effect of plastic deformation created by bending of a sample on the photoconduction spectra is studied. We found that plastic deformation of the sample results in suppression of the peak at h omega = 0.6 eV.