The article discusses the criteria for classifying middle-range theories in criminology. The middle-range theory was developed by the American sociologist Robert Merton in his Social Theory and Social Structure. The article aims to analyze the specifics of applying the criteria of the middle-range theory to criminological research. General (analysis, synthesis, systemic-structural) and specific (biographical analysis, statistical analysis, comparative historical analysis, expert assessment) methods were used in the study. As a result of the study, the following conclusions were obtained. The developing nature of criminology is due to the fact that its object and place in the system of legal and social sciences are not clearly defined; criminology has no independent research methods and uses methods developed in other sciences, primarily sociology and statistics. Scientific schools in criminology are possible as they employ various and unique approaches to the study of its object, specific methodologies for studying particular problems, and have founders and followers of such approaches. The systems approach used in the study allowed the authors to consider the place of criminological research in social sciences and to determine other criteria of middle-range theories in criminology. These criteria include: the attribution of criminology to social and legal sciences; conclusions about specific phenomena or their specific aspects (rather than about all elements of the object of criminology) in these theories; attribution of some research to an intermediate link in scientific knowledge. Criminology is classified as a social science because of its subject matter, which includes such social phenomena as crime, the determinants of crime, the identity of the criminal, and crime prevention, as well as its methods developed by other social sciences. The attribution of criminology to legal sciences is due to the fact that its main object of study is crime, consisting of offences defined by the criminal law. Criminological middle-range theories do not contain conclusions about all elements of the object of criminology; they contain the results of studies of certain types of crime, the identity of the offender, the determinants of crime, crime prevention. The fact that a number of studies occupy an intermediate place in scientific knowledge means that middle-range theories are located between research on the most general issues of criminology and applied criminological research on a specific problem.