This paper presents a clear interpretation of the pole migration on the real axis where many root loci starting from different poles lie together or conflict with one another, by introducing the concept of a pair of real roots. Except in the case of a single root locus, the root loci on the real axis appear always as a pair. Just like the complex number, a pair of real roots is expressed in two parts and the whole root loci for both real and complex roots are plotted in the conventional rectangular coordinates as continuous curves, by which the migration of each pole on the real axis is shown very clearly. Three examples are given.