Electroosmoticflow (EOF) applied in micropump is a novel technology, which will be widely applied in micro total analysis systems (μTAS) and drug delivery systems. EOF velocity in microchannel depends on the zeta potential (ζ), the electric field (E) parallel to the microchannel and so on. Electric field can be decreased if ζ can be increased, which can reduce the disadvantage caused by the high electric field voltage. This paper discusses the relationship between EOF velocity and ζ, E, to realize this concept. Through building mathematical model, this paper analyzes the effects of changing ζ and E on EOF velocity, which provides the microfluidics control theory basis to design EOF micropump and presents a new subject of manufacturing micropump process.