The auxiliary word of「tsutsu」is usually used as written language in modern Japanese. It however was used as a colloquial form as well as written language in ancient Japanese. The article has studied the meaning of the classical language of「tsutsu」, focusing on the examples from classical literatures and commentaries. The classical language of「tsutsu」functioned as an auxiliary verb rather than an auxiliary word, and expressed emotion and impression when it was used to close a sentence. As an auxiliary word, it represented continuation, repetition, and parallelism, and thus its usage was different from other general auxiliary words. In addition, the study has looked into the meaning of verbs that connects to「tsutsu」through『Manyousyu』,『GenjiMonogatari』,『HekeiMonogatari』,and『Tsuredzurekusa』. In『Manyousyu』and『GenjiMonogatari』, which are the literary works of the Nara and Heian Periods when「tsutsu」played a role as everyday language, there were a number of cases wherein「tsutsu」connected to verbs that express human thought and emotion. We can also find many cases in which it connected to verbs that do not directly affect objects. This tendency was not found in『HekeiMonogatari』and『Tsuredzurekusa』, which were the works of the Kamakura period when「tsutsu」began to be used as written language. Hence, we could recognize that there is a correlation between the meaning of verbs and the conjunction of 「tsutsu」.