Starting from the principle that an effective multivalued algebra system can reflect the physical process in multivalued circuits

this paper proposes a set of operations which may describe the interaction between signals and switch elements in multivalued ECL circuits. The physical counterparts and relative properties of these operations are discussed

and the switch-signal theory suitable to ECL circuits is established. Some basic quaternary ECL circuits are designed. They are proven to have correct logic functions and ideal characteristics by using SPICE program.