The book is dedicated to the participation of a lawyer in evidence in civil and arbitration proceedings. The work analyzes in sufficient detail the powers of a lawyer to prove at all stages of legal proceedings, including when determining the subject and limits of evidence, collecting and presenting evidence, participating in their research and evaluation activities in civil and arbitration proceedings. Issues of an ethical and psychological nature are also touched upon, as well as many other things that deserve theoretical and practical interest. The book can serve as a good practical guide for lawyers, judges, prosecutors, teachers, graduate students and students of law schools. The author of the book is A. A. Vlasov, a graduate of Moscow State University, candidate of legal sciences.