This paper aims to describe Volitional Expression of the subordinate clause, through a contrastive analysis between Korean and Japanese. This paper focuses on the relationship between the interdependent subordinate clause and the principal clause in complex sentences. This linguistic phenomena is comparable to Korean causal/conditional expressions and noun clause expressions. There is a weak relationship between the subordinate clause and the principal clause in「ga; が: 가/이」noun clause. There is a strong relationship between the subordinate clause about the principal clause in「no;の:의」noun clause. There is a weak relationship between the subordinate clause and the principal clause in「nara:なら:거든」 conditional clause and「kara;から:니까」causal clause. Occasionally, sentences, containing [nara:なら] conditionals can be considered as simple sentences. A disparity in the independency between the subordinate and the principal clause results in a plural subordinate clause. The functionality of the subordinate clause depends on the degree of its subordination in relation to the principal clause. The subordinate clause and the principal clause is related to the speaker’s volition through their selection of speech acts.