The technique of passive differential optical absorption spectroscopy (DOAS) is based on fingerprint absorption of probed gas species, which enables simultaneous monitoring of a variety of pollutants found in the atmosphere using scattering light as light source. We describe an optical remote-sensing instrument which is based on imaging spectrometer that permits spatially resolved mapping of atmospheric trace gases by passive DOAS method. The applications of one spatial dimensional measurement of gas cell and imaging of the nitrogen dioxide over city main road were also reported in this paper. With scattered sunlight as the light source, the system based on imaging spectrometer simultaneously acquiring spectral information in one spatial dimension, the second spatial dimension is scanned by a moving mirror.