GaN films have been grown on a-plane (11 (2) over bar0) sapphire substrates by plasma-assisted MOCVD using TMGa (trimethylgallium) and plasma-cracked N-2. The crystallinity, electronic properties and optical absorption of films were characterized by X-ray diffraction, Hall-van der Pauw measurement method and UV vis spectrometry, respectively. It was found that GaN films grown at 600 degreesC have a wurtzite structure with (0 0 0 1) orientation and films grown at 640 degreesC have a mixture of crystallites with phase dominant peaks of (10 (1) over bar0). The carrier density of GaN film grown at 600 degreesC is n = 5 x 10(19) cm(-3) and its bandgap is 3.4eV. As the N-2 flow rate increases, the carrier densities decrease to n = 1.7 x 10(19)cm(-3) and the mobility increases.