In Russian linguistic, the merging property of words is one of the topics considered when studying the way words are put together. This property can be observed at two levels: syntax and semantics. The Russian linguists study the merging property of words in subordinate phrases and based on this, consider one word in each subordinate phrase as the head and the other one as the complement. There is a semantic relationship between the heads and the complements in each subordinate phrase, which is known as syntactic relationship. The Russian linguists consider this relationship among words in each phrase as the general meaning of the phrase and on the basis of this divide them into different categories. This article studies the nature and function of the merging property of words in Russian phrases.