A phenol-formaldehyde resin (PFR) and a bituminous coal (SH) were pyrolyzed at various temperatures. The structure and the char-NO reactivity were analyzed in order to examine the effect of pyrolysis temperature on the micro-structure of the resulting char and further on the reactivity towards NO. Micro-structure of the char samples was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Raman spectroscopy. It was indicated that the micro-structure of PFR char and coal char experienced remarkable changes during pyrolysis, which resulted in the decrease of phenolic OH, aromatic hydrogen and more ordered structure. The pyrolysis temperature showed a weak impact on the reactivity of PFR char but comparatively remarkable impact on that of coal char at lower reaction temperature. Mineral matter in coal char presented a weak effect on the reactivity.