We have successfully prepared wurtzite (Ga,Mn)N epitaxial layers using RF-plasma-assisted molecular beam epitaxy. Highly resistive (Ga,Mn)N epilayers show primarily paramagnetic behavior. The results of compositional, electronic and magnetic characterizations on the epilayers suggest that 60% of Mn content in the epilayers substitute for Ga on sub-lattice sites. For epilayers with very high Mn concentrations (similar to10(21) cm(-3)), Curie-Weiss analysis has revealed the effective spin number S approximate to 2.5 together with the positive paramagnetic Curie temperatures. This suggests the presence of ferromagnetic spin exchange between Mn ions. (C) 2002 Elsevier Science B.V. All rights reserved.