Summary. The visual data flow environment called V4Miner simultaneously uses a set of interactive techniques, visualization methods and machine learning algorithms to discover knowledges in an intuitive, interactive, retroactive way. A data mining task is easily expressed by a graphical visual data flow where a method is represented by a graphic component of JavaBeans, the communication between methods is based on a data bus. The user can create and control completely the process of extraction without any programming. The visual data flow makes it possible on the one hand to reduce the complexity of a task of analysis and on the other hand to be able to improve quality and users’ comprehensibility of the results obtained. We studied some biomedical data mining tasks with Kent Ridge Bio Medical Dataset Repository.