This study investigated effects of sentence-final particle “no$rdquo; on sentence memory in order to clarify whether the non-referential function of “no$rdquo; could trigger fortuitous interaction in discourse. Sentence-final particle “no$rdquo; has two basic functions in terms of a local chain of communication. One is to imply a message sender's vague commitment to the utterance. The other is to imply awaiting the receiver's involvement in the unsettlement. Based on psychological studies on memory, it was predicted that the both functions of “no$rdquo; would promote memory by awaking receivers' attention in comparison with declarative sentences. In experiment 1 each of twenty simple sentences was visually presented one by one and read aloud in either declarative sentence or adding “no$rdquo; sentence. In experiment 2 a mixed list of ten declarative and ten adding “no$rdquo; sentences was visually presented one by one and read aloud. The results of the two experiments showed that the sentence-final “no$rdquo; sentences were significantly more memorized than the declarative ones. In experiment 3 sentence-final “yo$rdquo; was used in order to examine other sentence-final particle could influence on memory. The “yo$rdquo; implies a message sender's clear commitment to the utterance that specifies a new plot. The result showed that the “yo$rdquo; did not have any effect on memory.