Abstract: Discusses methods for the resolution of ambiguity of multiple tragets using residues’ difference look up table, in a pulse Doppler radar working in a four PRFs system. For a four PRFs’ radar system, the resolved results calculated by the residues’ difference look up table method from any two of the target distances detected are equal. With this the ambiguity of multiple targets can be resolved. The method based on residues’ difference look up table as presented in the paper can resolve the ambiguity of multiple targets correctly, especially when the number of targets are few and the system design is well done in choosing appropriate PRFs.