We report the realization of p-type behavior in ZnO thin films, which are prepared by codoping method using Ga (donor) and N (acceptor) as the dopants. Especially, using active N formed by passing N 2 O gas through an electron cyclotron resonance (ECR) plasma source is quite effective for the acceptor doping. We have observed a room temperature resistivity of 2 ·cm and a hole concentration of 4 × 10 19 cm −3 . These values are enough high for practical applications in various oxide electronic devices.