The article deals with the discourse of aggressiveness. The study is based on the material of the Ukrainian diary discourse. The research material is the diary entries of Ukrainian diarists. A complex of general scientific and special research methods is used: analysis and synthesis, observation, definition, systematization. It enables generalization and specification of the theoretical foundations of the study of the speech aggression problem in the diary discourse. The investigation focuses on the phenomenon of speech aggression from the latest positions of cognitive and communicative paradigms – the selected language facts are described and systematized; contextualized fragments of diary texts containing speech aggression are identified and described. The article proves that verbal aggression is most evident in the context of daily discourse. Discourse semes of aggressiveness at the lexical level have significant opportunities for the diarist's verbal realization of his negative perception of a certain situation or the interlocutor`s personality. They form the evaluative content of diary communication reflecting its peculiarities. A convincing feature in the semantic field of aggression is the high semiotic density of negative behavioral characteristics and emotional evaluations. The evaluative content contained in the aggressiveness discourse semes allows the diarist to express his disapproval, rejection, negativism towards the opponent or the subject of the dispute. The analysis of the actual material proves that verbal aggression in the diary discourse is a special type of speech behavior of the diarist. The internal structure of text messages in this type of discourse serves as a means of rendering intolerant information, containing a wide range of specialized and non-specialized invectives.