The article analyzes the conceptual principles of legal regulation of freedom of peaceful assembly. The purpose of the study is to analyze the procedural principles of the constitutional right to peaceful assembly, including international legal standards prior notification on holding a peaceful assembly and the mechanism of its realization in Ukraine. The author found that the provisions of the law concerning the notice should include only the notification of intent to meetings and not require the submission of a request for permission to hold it. Term advance notification of peaceful assembly shall be the guarantee of this right. During that period the authorities and local governments are required to take a number of measures to ensure the through conduct of peaceful assemblies, maintenance of public order, the protection of the rights and freedoms of others. The main problem at present state in Ukraine in the sphere of freedom of assembly is a requirement to adopt a special law. Provisions of the draft bills of studied questions have been analyzed.