The purpose of this paper is to clarify the types of expression and functions of intonation using long note ‘-’, ‘∼’, ‘…’ in Japanese internet-based language. Internet-based language has a shortcoming which cannot transfer informations of prosody messages. But many internet-based language users in Japan are using and making the methods of expression of prosody messages, expecially intonation. Thus, we focus on the types of expression and function of intonation using long note ‘-’, ‘∼’, ‘…’ in Japanese internet-based language on a youth bulletin site is called Casphy.com. As a result of investigation, we clarified that the intonation in Japanese internet-based language has five types of expression, ‘short rise(↑)’, ‘long rise(↗)’, ‘rise-fall(⇅)’, ‘flat(→)’, ‘long fall(↘)’. And we clarified the intonation in Japanese in internet-based language has nineteen functions. Expecially three functions ‘affinity’, ‘lingering’, ‘rising of feelings’ are unique functions in Japanese internet- based language.