There have been different approaches to the phenomenon of ellipsis in both world and modern Azerbaijani linguistics. Although ellipsis is widely studied between the sides of compound sentences, but we believe that taking the wider and more diverse evolutionary processes in composite sentences, especially in complex sentences into consideration the fact of ellipsis in these constructions needs to be studied more deeply. The article provides detailed information on the characteristics of the formation of elliptical shapes of subordinate compound sentences. As you know, a subordinate compound sentence consists of two components: a main and a subordinate sentence. The ellipsis observed in a subordinate compound sentence does not manifest itself in the form of omission of any part of a sentence as in a simple sentence, but in the context of omission of the whole mai or subordinate sentence. Although the phenomenon of ellipsis can manifest itself in both components, the article deals with the ellipse observed in the main sentence. The article also notes that the phenomenon of ellipsis is naturally more characteristic of dialogic speech. Because this event occurs not as a deliberate, pre-planned form, but as a result of the natural regularity of language. It is clear that the basis of dialogic speech is question and answer sentences. Some of the question and answer sentences, in turn, form the components of a subordinate compound sentence, forming a dialogue unit. In some dialogues with such a construction, the phenomenon of elliptism manifests itself in the question sentence and in others in the answer sentence. It also provides detailed information on the role of many factors in the emergence of this language fact, in particular, the tendency of the language to save. The article also reflects and compares the views of world linguists on the phenomenon of ellipsis. The fact of the language which is dealt with is substantiated by concrete examples.