The dissertation is devoted to one of actual problems of modern linguistics namely the study of the ccasionalisms in the texts of Ukrainian mass media at the beginning of the XXI century. In particular, the main theoretical points of the occasionalism issue have been summarized, the current linguistic criteria of differentiation of the terms “an occasionalism” (unusual creation) / “a neologism”, “a potential word” (usual creation) have been considered, various signs of occasionalisms have compared to other linguistic innovation, the main features of the occasional units have been characterized and the range of issue corrected with the phenomenon of occasionalism has been outlined. The main intra-linguistic and extra-linguistic factors that determined the dynamics of their creation in a marked period have been analyzed. The influence of external factors is more expressive and brighter, and intralingual less weighty. Occasionalisms have been formed on the basis of the lexical meaning of the image of the unit, their imagery and stylistic coloring and word-formative significance formant. In dissertation, the thematic groups of the innovation have been determined and have different degree of filling. The most complete are the following thematic groups of vocabulary: socio-political, artistic, economic, markings on technical innovation and computer technology, events and subjects of household culture. Smaller units have combined the thematic group of occasionalisms from the field of sports, ecology and medicine. The productivity of relevant word-formation types has been determined for modern Ukrainian mass-media space, including occasional (contamination, substitution, splicing, “remittame” of affixation or separate segments of the word, hendiadys) and usual ways (word, chainfusions, suffixes, prefixes). The stylistic functions of occasional derivatives have been analyzed, their degrees of expressivity have been observed on the background of language usual new formations, in particular potential words. There were cleared up that occasionalisms perform in media texts evaluation, emotional and expressive, voluntative and aesthetic functions. They reflected the emotional and expressive shades, the evaluative aspect in such lexemes is more important than informative, in fact the production of occasionalisms have been aimed at creating not just a new, but original speech unit.
