The problems of studying complex sentences, considered in the field of traditional syntax of Kyrgyz linguistics, are studied from different points of view and are not fully scientifically justified, which can be traced in general textbooks, scientific and theoretical works. Therefore, the relevance of the article is due to the need to study the issues of complex sentences in the framework of the syntax of the Kyrgyz language. In addition, some scientists note that the issue we are considering is still controversial among scientists. For example, the scientist M. V. Muratalieva, in her scientific work on “Complex Sentences in the Kyrgyz language”, published in the 1980s, identifies the main types of complex sentences and examines the differences between them. The paper describes the relationship between equal simple sentences that have independent semantic meanings as part of a compound sentence, and also considers the relationship between the main sentence and one or more subordinate clauses. The author sets the main goal of the study to study the possibility of using a simple sentence as part of a complex sentence separately, the presence of simple sentences in their structure and structure of features that distinguish them from complex sentences, and as a result, comes to the conclusion that it is unacceptable to separate individual parts of a complex sentence, thereby excluding the possibility of using and considering them outside of complex sentences. Thus, simple sentences in a compound sentence are closely interrelated with each other, forming a unity not only in semantic terms, but also in structural terms.