Studies of surface and bulk chemical properties of minerals can aid in understanding the mechanism of collector attachment and also the behavior of the oxide minerals during flotation process. In this paper, the surface and bulk properties of oxidized zinc ore samples were examined by means of X-Ray Photoelectron Spectroscopy (XPS) or Electron Spectroscopy for Chemical Analysis (ESCA) andenergy-dispersive X-Ray analysis (EDX).Three size fractions,-250+200µm;-200+150µm and-150µm, were examined XPS results show that there are no significant differences between zinc percentage nor the for other elements of the three size fractions. According to these results, it can be concluded that the measurement of surface composition by means of XPS are approximately the same for all three-size fractions. A comparison between the data obtained from XPS (surface composition) and from EDX Analysis (bulk composition) showed that there are some differences for some elements. For example, Si, Fe, and Al content in the oxidized zinc ore samples. These differences between XPS and EDX technique could be based on the amount of measured oxygen for each technique.