The peculiarities of training process design have been analyzed, the systems of organizing educational process of the preliminary basic preparation period have been theoretically developed, based on the account for the key fitness indices, which determine the performance in the competitive activities of athletes in modern pentathlon. Objective. To study the current state and actual problems of physical training of pentathlon athletes at the stage of preliminary basic preparation. Methods. Analysis of scientific and methodological literature. Results. In the process of training pentathletes the mutual influence of training loads in certain types of all-around inevitably emerges and actively manifests. Therefore, one of the basic conditions for successful training of athletes is the rational distribution of training loads from the complex disciplines, the ability to properly combine all components of sports preparation, that is to make the most of the positive influence of one type of pentathlon upon another. The problem of designing microcycles at the initial stages of long-term improvement remains poorly understood, and therefore requires further investigation. In the process of long-term training of athletes a very important role is played by rational alternation of loads and rest in the microcycle. Not all coaches use versatile training, bypassing important components of the training structure. They also do not take into account the risk of injury to young athletes, especially at the stage of preliminary basic training, because at this period the important age-related changes occur in the child’s body. By irrational selection of exercises and alternation of loads, coaches fatigue the young body of the child, thereby reducing the efficiency of competitive activity. It is planned to develop training programs with account for age peculiarities, as well as traumatism at the stage of preliminary basic training.