Introduction. The research relevance is in the need to improve the process of physical education of 5-6 year-old children based on the development of sound quantitative criteria of pedagogical control over the level of motor abilities development. Research purpose is to identify the features of development of general and strength endurance in 5-6 year-old boys and girls and substantiate the standards for their assessment. Materials and methods. The study was carried out with the participation of healthy 5-6 year-old children who do not have medical contraindications for attending physical education classes. The sample size exceeded 1,600 preschoolers in the age group under study. The research methods included motor readiness testing and mathematical-statistical processing of the obtained data. The statistical significance of the differences was determined by Student’s t-test for independent samples and Fisher’s F-test. Research results. The study obtained extensive information about preschoolers’ motor fitness. It was found that 5-6 year-old children are statistically significantly inferior to 6-7 year-old preschoolers in terms of the level of development of general (t=9.57; p<0.001) and strength (t=27.11; p<0.001) endurance. The features of motor fitness among 5-6 year-old children, conditioned by their gender, were also revealed. The comparison of the average values of a general endurance indicator made it possible to establish that boys are statistically significantly (t=2.65; p<0.01) superior to girls. It was also revealed that the results of the sit-up test among the boys differ in more significant variability (F=1.36; p<0.01). Taking into account the results obtained, modern, relevant and representative comparative standards have been substantiated for the diagnostics of general and strength endurance. On the basis of a standard scale for the value of general and strength endurance indicators, five assessment scales characterizing low, below-average, average, above-average and high levels of development were revealed. Conclusion. The developed standards make it possible to objectively assess the dynamics of the development of general and strength endurance in 5-6 year-old boys and girls in physical education classes in preschool educational organizations. They can be used as a means of pedagogical control over the level of motor abilities development of preschoolers in the age group under study.