ZnO nanowires UV photodetectors with different interdigital electrode distances were fabricated by using a dielectrophoresis method in this work. The multiple horizontal nanowires array integrated that photodetectors were composed by lots of paralleled ZnO nanowires. Experimental results showed the responsivity of the detector with the electrode distance of 6.5 渭m could reach 40 A/W at 10 V bias. It was also observed that the rising and decaying stages of the time-resolve photocurrent were both two processes, which was possibly attributed to the relaxation processes of the surface states and the deep level traps.