Abstract: According to the classification of mechanical impedance and the requirements for the advance of electrical engineering, it is proposed that electrical impedances are classified into current impedance (admittance) and charge impedance (admittance). By sudying the contradictions among eight functions which are the impedance and the admittance functions of current and charge in RC branches, and of displacement and velocity in SD (spring-dashpot) branches, and by using the signal flow graph topology, the author presented some network transformation methods of TRANSPOSITION, NVERSION, SIMILARITY and their combinations, and established EIGHT TRANSFORMATION RULES. The transformation relationships of configurations among voltage, current, charge, force, displacement and velocity corrective-compensative networks, as well as the algebraic substitution relationships of their transfer functions have been given by the EIGHT RULES proposed in this paper. Then a complete system of RC and SD networks is composed. Shortcomings involved in some references are also pointed rut. The analogy of the impedance (admittance) functions and the proposition of the THREE TRANSFORMATIONS and the HIGHT RULES enriched the simulation theory, and are also valuable for the network analysis in other scientific and technical domains.