The article examines the theoretical foundations of mentoring as a system of relationships in which one person (mentor) provides support for new knowledge, development and progress of another person (student, mentee). A study of legislative and institutional support, as well as the results of practical implementation of mentoring as a form of professional socialization at enterprises (MTS Ukraine, Coca-Cola Beverages Ukraine, 3M Ukraine, KPMG in Ukraine, JSC Ukrzaliznytsia, etc.) was conducted. Positive results of mentoring determined the increase in the level of internal system of training of employees, the development of own know-how of enterprises, increasing the level of satisfaction of employees with work, the formation of high-quality intellectual and human resources potential to ensure digital transformations at enterprises, the elimination of conflicts, increasing the level of motivation, the introduction of new rules and traditions of the company, increasing the level of relevance and reliability of Management Information, expanding the network of international contacts between employees (exchange of experience, solutions and ideas), improving the skills of employees and their performance, etc. The disadvantages of implementing mentoring systems of enterprises include resistance from mentors and their unwillingness to share experience with young colleagues, as well as the spread of mentoring practices only for new employees of enterprises, young specialists, beginners in a particular profession, undeveloped feedback between mentor and mentee (mutual mentoring). Using the method of theoretical generalization, analysis and synthesis, the article examines the analytical tools of mentoring activities, which are summarized in four groups: a targeted questionnaire survey of respondents, an online survey in the internet environment, a critical analysis of literature sources and the regulatory framework for the problem, a combination of various methods (questionnaire surveys, interviews, demonstration projects, etc.). In the context of deepening the practice of combining various methods of analysis, in order to increase the effectiveness of mentoring activities, when implementing analytical work, it is recommended to use methods of personnel assessment: 365 degrees method, Hay method, point-factor assessment, assessment center. The article outlines the essence of the recommended methods and points out the advantages of using them when analyzing mentoring systems in enterprises.