ENThe subject of this study is complicated compound sentences. Linguists describe these sentences very different. But these sentences like regular compound sentences can be divided into four types: 1) compound; 2) comparison-adversative; 3) disjunctive and 4) causative-consecutive. On the bases of sentences connectives logical semantic relation of components and sentence component structure, all the complicated compound sentences can be classified in the same ways as regular compound sentences. This would allow to avoid mixed complex sentences as independet sentence type, and all the complicated compound sentences would be classified according to unified criteria.