Nitrogen-doped fullerenes were synthesized by vaporization of graphite under the atmosphere of nitrogen and helium mixture. The types of nitrogen incorporated into the fullerenes were studied by near edge X-ray absorption fine structure and temperature programmed combustion. The results show that, in addition to the substitution of carbon atoms of the fullerene cages, nitrogen was also introduced into the fullerenes as HCN and CN which are probably chemically adsorbed on the cages. (C) 2002 Published by Elsevier Science B.V.