Iron catalysts precipitated on brown and bituminous coals promote conversion reactions of coal nitrogen to Nz during pyrolysis at 900 degrees C, and the NS evolved from the brown coal arises mainly from char nitrogen(char-N). The present study, thus, focuses on clarifying the effect of the iron on char-N functionality and elucidating interactions between the two mainly with X-ray photoelectron spectroscopy(XPS). The N Is spectra of brown coal chars revealed that the catalyst lowered the ratio of pyrrolic-N/pyridinic-N irrespective of the depth of the char, indicating the preferential formation of Nz from pyrrolic-N. In the Fe 2p and N Is XPS spectra of the Fe-bearing chars, Ar sputtering removed surface iron oxides to expose the metallic phase and concurrently increased the proportion of pyridinic-N with the corresponding decrease in quaternary-N. It is suggested that there are strong interactions between the iron and char-N even in the process of N-2 formation. Iron particles were more finely dispersed on the brown coal char and in closer contact with it, which accounts for higher conversion of char-N to Na. A schematic mechanism for this conversion process is discussed in terms of solid-solid reactions of metallic iron and char-N.