Abstract: When microfocusing monochromatic Al target XPS experiments are used to carry out, it is necessary to make X-ray irradiation area, electron neutralization area and photoelectron acceptance region focus on the same point. However, when samples are analyzed at an inappropriate height, the above can not centre on the same area. In such case the intensities of core lines are likely to reduced, and for the elements with relatively high binding energy, the peaks are likely to broaden, and sometimes split in double.