Abstract: To solve the problem of the remaining oil production in complexed fault block reservoir of Xianhe oil zone, a set of active micro-sphere plugging agents have been also developed using the method of latex or micro-latex preparation. The research and application of active micro-sphere plugging agent have been also carried out. Based on lots of lab experiments, physical and chemical parameters of the active micro-sphere are evaluated including original size, shape and form, expansibility, stability, plugging results, etc. Applicability is also evaluated by modeling the reservoir conditions. As a result, micro-spheres of different ranks used for different permeability in Xianhe complexed fault block reservoir are chosen as a micro-sphere system that adapts to the reservoir characteristic well. In the end, field test of deep stereo profile control is carried out. In conclusion, deep stereo profile control with active micro-sphere can be actually realized of low concentration, little dose and injection on line, which increases swept area and volume of injected water, then reaches the aim of EOR.