The optimal feature of anticoagulant and fibrinolytic of the vascular wall provides the major homeostasis process in the whole body of a mammal. It is impossible to track in clinic peculiarities of the earliest change in vascular hemostasis in a debut of metabolic syndrome formation. Thus, it dictates the necessity of conducting experimental researches on laboratory animals with modeling of metabolic syndrome within them. The aim of the research is to examine early stages of vascular hemocoagulation weakening control in conditions such as the formation of metabolic syndrome. The study used 61 male-rats of Wister line at the age of 2.5-3 months. The animals were subdivided into two groups: 32 rats received 10% fructose dilution with free access for drinking, and 29 rats to the control group. Biochemical, hematological and statistical methods of investigation were applied. We found that in high fructose level, there is a fast evident of a weakening of the anticoagulant and fibrinolytic activities of vascular endothelium as well as the body mass gain and development of biochemical abnormalities, which is typical for metabolic syndrome. The early weakening of vascular control over hemocoagulation turns metabolic syndrome into a very dangerous state because of thromboses, which may take place even at the very beginning of its development.