The aim of the article is to describe the system of pseudo-copulas in the Russian language of the XVIIth century. Pseudo-copulative verbs of the XVIIth century were less numerous and less used than in Modern Russian. Pseudo-copulas of the period are characterized by diversity of syntactical characteristics; this peculiarity characterized even pseudo-copulas that had similar meaning. Some pseudo-copulas were limited in their use to some types of texts and their meaning differed from modern meaning. All these facts permit to conclude that the system of pseudo-copulative verbs was in the making.