This paper presents the current effort of detecting trace species nitrogen dioxide (NO2) by using photofragmentation and Radar REMPI. In this technique, a single near UV laser beam near 381 nm photofragments nitrogen dioxide (NO2) and resonantly ionize nitric oxide (NO) by means of 2+1 REMPI process. Coherent microwave scattering in-situ measures the total electron number in the laser-induced plasma. The resultant REMPI rotational spectra of NO2 and NO have distinct difference at 381.794nm which is rotational line and could be due to higher vibrational excitation of NO photo-fragments from NO2. It provides a method of measuring two species directly which will be helpful for combustion diagnostics and hazardous chemical compounds detection.