The photoelectrochemical properties of GaN particulate film electrode on Ti substrate were investigated. GaN particulate film electrode was fabricated by means of doctor blade technique. Two kinds of method were used to improve the connection between GaN particles. One is a heat treatment of GaN particulate thin film with LiNH 2 and another one is a heat treatment with TiCl 4 . From the results of the photoelectrochemical properties, GaN electrodes showed n-type semiconducting behavior in 1.0 M HCl electrolyte under UV irradiation. The high photocurrent response was achieved in the electrode with LiNH 2 treatment and TiCl 4 treatment because of its better connection of each GaN particle.