This paper presents the results of a production experiment on the intonation of sentences containing a negative polarity item (NPI) in Tokyo Japanese. The results show that NPI sentences exhibit a focus intonation: the F₀-peak of the word to which an NPI is attached is raised, while the pitch contour after the NPI-attached word is compressed until the negation. This intonation pattern is parallel to that of wh-question, in which the F₀ of the wh-phrase is raised while the post-wh-contour is compressed until the question particle.