Two suitable base stations were set up on the rooftop of the building of Department of Agricultural Chemistry, TARI and adjacent the experimental plot of precision agriculture, respectively, to determine the accurate coordinate for sampling and fertilization. According to the best real time kinematics positioning, we could transmit the positioning coordinate to a field computer for estimating the fertilization rates by a decision support system. Setting up the base stations of the global positioning systems to develop the techniques of real time positioning could spread and applicant any relational research on precision agriculture. Combination and application spatial data and property data on agricultural machine could catch the objectives for auto control of agricultural cultivation.