The aim of the diploma thesis is the complex interpretation of legal acts in commercial legal relations. At first from the perspective of law doctrine, when firstly specify the possible methods of interpretation, further the interpretation from the perspective of civil law and finally from the perspective of commercial law. The whole first part is finished by the comparation with Italy law and interpretation of legal acts. The second part of thesis deals by interpretation of legal acts from the perspective of case law firstly generally after that with interpretation of individual cases of various possible problematic provisions and their subsequent analysis and recommendations for potential participants in the contractual relationship. The conclusion of the thesis is assess whether the theory corresponds to practice and subsequent recommendations for participants relationship, how to behave in order to avoid any misunderstanding and subsequent litigation.