In this work, based on the current provisions of the Constitution of Ukraine, the CPC of Ukraine as of February 1, 2020 and new legislation on judicial and law enforcement agencies thoroughly outlined the main doctrinal provisions and content and problems of competition in modern criminal proceedings, recommendations on resolving problematic issues of criminal justice, taking into account the rule of law and the principles of legal certainty and proportionality, the provisions of international legal acts and legal positions of the European Court of Human Rights. issues, flaws and gaps in legislation, and resolving difficult situations in investigative and judicial practice, implementation of the principle of presumption of innocence, problems of evidence, standard of proof beyond a reasonable doubt, protection of rights, honor and dignity and safety of participants in criminal proceedings, (investigative) actions, ensuring the objectivity of investigations and the independence of investigators and detectives, the use of house arrest and other precautionary measures, jury trials and proceedings on the basis of agreements, rehabilitation of persons illegally prosecuted, development of procedural form and strengthening procedural guarantees justice. Prospects for the development of criminal procedure law and jurisprudence are revealed. State Bureau of Investigation, customs and tax authorities, students, undergraduates, students and cadets of higher law schools. It will be a suitable helper for those who learn the basics of criminal procedure law, as well as for those who seek in-depth study of criminal procedure.