The focus of the article is Thematic Progression as a text and a genre forming phenomenon. Thematic Progression contributes to the cohesive development of any text, the distribution of given and new information of which needs to follow certain patterns. Thematic progression patterns deal with the set of meaningful sense groups which constitute a coherent text. Basic thematic progression patterns are: simple linear thematic progression, thematic progression with a continuous (constant) Theme, thematic progression with derived Themes and thematic progression with a split Rheme. They are peculiar to many languages. However, texts of different genres and the same language exhibit different patterns of Thematic Progression. This indicates that Thematic Progression, its patterns and their varieties are genre specific. To prove this, the article dwells on the Theme progression patterns and peculiar features of their Theme-Rheme organisation in texts of literary and legislative genres. While linear-constant thematic progression patterning is typical of a literary text, a legislative text is mainly based on the constant-linear thematic progression pattern. Constant-linear thematic progression patterning in the legislative text contributes to its informativeness, argumentativeness, unambiguity, and detailed specification of the given information. In comparison with the legislative text, the literary text has a variety of thematic progression patterns made of linear thematic progression, derived thematic progression and elliptical progression types. Regular linear-constant thematic progression patterning employed in the literary text helps to unfold textual information successively that contributes to its coherence and more effective perception.