The research based on sentences expressed by conjunctive proposition, aimed at solving why the conjunctive proposition that depend on the same logic can perform differently in forms of language.

This paper,by constructing a logical sketch map about relation of values,mainly depicts 4 equivalent expressions,4 contradictory expressions and 32 implications expressions between conjunctive proposition of modality or disjunctive proposition of modality and modal proposition of conjunctive form or modal proposition of disjunctive form.

This paper,by constructing a logical sketch map about relation of values,mainly depicts 4 equivalent expressions,4 contradictory expressions and 32 implications expressions between conjunctive proposition of modality or disjunctive proposition of modality and modal proposition of conjunctive form or modal proposition of disjunctive form.

This paper carries out full analysis on Aristotle s theory on categorical proposition and points out that he introduced,for the first time in logic history,term variable,established opposition matrix,and laid basis for syllogism.

Matching up to the three indispensable conditions to conversion inference of categorical proposition in traditional logic is in fact proved to be the restriction of interrelation between lexical items that the conversion inference concerns, as is visually cleared by Eulerian graph.

Is it universally adequate that the reasoning rule "if a term is not distributive in the premise, it is still not in the conclusion" in the reasoning consisting of categorical propositions? This is a question that has not been resolved in logic.

In our country, logic circles have different views on three theory problems :the definition of compound proposition , the definition of disjunctive proposition and the dignity of exclusive disjunctive proposition.