This paper describes the influence of the main factor on the colorful titanium oxide reacted film fabricated by EDM (Electrical Discharge machining). In our process, copper, together with pure titanium sheet, was used as anode and cathode (workpiece) respectively, and dielectric medium involved in the study was tap water. From the figures and tables shown, we can observe that colors of titanium oxide reacted films change with the increase of open voltages (0~240) from yellow (10 V), purple (20 V), indigo (30 V), golden yellow (70 V), to peach (100 V), blue (130 V), yellow green (180 V), pink (240 V). The other open voltages produce mixed colors between those created by neighboring voltages. Moreover, XRD as well as EDS analysis have made it evident that the structure of the reacted film mentioned above is $Ti_2O$ other than $TiO_2$ and the rise of pulse duration and interval will cause non-uniform color distribution. Compared with anodizing process, the Electrical Discharge machining approach we developed for generating colorful titanium oxide reacted film in the paper is much simpler, faster, cheaper and have plenty of advantages still in environment protection and hazard avoidance.