Relevance of article is caused by objective character of eurointegration process in Ukrainian economy and complex character of effects of eurointegration that make an impact on economic security of Ukrainian enterprises. Purpose of the article is analysis of impact of eurointegration process on economic security of Ukrainian enterprises basing on scenario approach. There are such research methods have been used in the article as descriptive analysis, scenario analysis, method of graphs, causal analysis, comparative analysis, SWOT-analysis. Notions of security, economical security and eurointegration have been shown. Attributes of notion of enterprise economic security have been considered. Results of eurointegration for Ukrainian economy have been shown. It has been proved that such results may be not only positive in the case of new abilities and open markets but they may become a threat for domestic enterprises. Scenarios of changes in national economy of Ukraine because of impact of eurointegration processes have been defined. Description of every defined scenario has been made. Such scenarios have been evaluated by criteria of desirability, possibility and time of implementation. Relation between analyzed scenarios of changes in national economy of Ukraine because of impact of eurointegration processes taking into account probabilistic cause-effect relations between defined scenarios has been shown. Results of such scenarios for economical security of domestic enterprises have been shown: characteristic of impact has been considered, most probable effects of implementation of such scenarios for Ukrainian economy on the whole and single activity subjects have been analyzed. SWOT-analysis to analyze impact of eurointegration on economical security of domestic enterprises has been adapted. Results of research are identifying and characterizing scenarios of changes in Ukrainian economy because of impact of eurointegration processes and characterizing of such scenarios impact on economical security of domestic enterprises. Scientific originality of results of research is in outlining scenarios of changes in Ukrainian economy because of eurointegration processes, making characteristics of such scenarios and relations between them taking into account impact of such scenarios on economic security of Ukrainian enterprises. Practical value of research results is in creating opportunity to provide adaptation of Ukrainian enterprises to eurointegration effects including strengthening of strong features and avoiding defined threats.