The article is dedicated to analyzing the conditionality, factors and indicators of heterogeneity and typologization of semi-presidential system of government. Attention is focused on the fact that semi-presidentialism is formally (institutionally and procedurally) and factually (politically and behaviorally) a heterogeneous system of government, and therefore it must be subjected to a comprehensive typologization and taxonomy. Since different types of semi-presidentialism, having positives (advantages) and negatives (disadvantages) and generating different risks and prospects, have dissimilar effects on inter-institutional relations, political process, dynamics of political regime change, political stability and socio-economic efficiency. In this regard, the author singled out the main taxonomies of semi-presidentialism into: president-parliamentarism and premier-presidentialism; unified majority system, divided majority system, divided minority system and unified minority system; presidentialized (highly presidentialized), premierized (parliamentarized) and balanced semi-presidentialism. In addition, the article traces the clusters of typologizations of semi-presidentialism and different approaches to their content. Therefore, it is argued that hypothetically there is no reason to speak of any established and perfect model of semi-presidentialism, even if it is concentrated in one region or one part of the world. Consequently, it makes no sense to compare semi-presidentialism as a whole, but instead it is much more efficient to appeal to its formal, factual and both formal and factual types/attributes as well as to political and socio-economic consequences caused by them.