The conventional way to emend errors of rational polynomial coefficients (RPC) is carried out by a polynomial transform between metrical image point coordinates and projective point coordinates from ground points,but in such a performance,the number of parameters will increase,and the number of parameters changes along with the form of the polynomial,which increases the utilization difficulties. In this paper,the authors consider that the nature of RPC is analogous to that of the attached polynomial parameters,and therefore propose that the errors of RPC parameters can be eliminated by emending partial RPC. The experimental results show that the ideal point precision can be attained without using additional parameters,and the precision is better than that of the traditional means.