Abstract: R₀-algebra is a class of logic algebra based on a systematic research on the formal deductive system L^*. The main aim of this paper is to investigate the structure of R₀-algebras, with the notion of normal MP-ideals in R₀-algebras introduced. The relations between normal MP-ideals and MP-ideals are given. The c
haracterization property and the extension property of normal MP-ideals are obtained. The normal R₀-algebras are completely characterized by the normal MP-ideals.

Key words: R₀-algebra, normal R₀-algebra, normal MP-ideal, MP-ideal