Abstract: The basis BL* system and BR0-algebra are studied.A schematic extension BL*Δ of BL* system is introduced by adding the unary connective Δ to BL*,and then the concept of ΔBR0-algebra is proposed.Morever,the Δ-filter of ΔBR0-algebra and corresponding properties are studied.Finally,the completeness of BL*Δ is proved by using the properties,and the generalized deductive theorem in BL*Δ is given.

Key words: fuzzy logic, BL* system, &Delta, -filter, completeness, generalized deductive theorem