The goal of this work was to determine a correlation between the VE-cadherin and circulating endothelial cells (CECs) blood levels at hemorrhagic fever with renal syndrome (HFRS) of different severity and research association between the VE-cadherin gene c. 1550T>C missense mutation and HRFS severity. Significant decreasing of the VE-cadherin and increasing of CECs blood levels in the course of the disease in all studied groups was established. Most prominent changes were found at severe type with complications. There was found a strong negative correlation between these two indexes. There was significant high frequency of homozygotic genotype *T/*T at severe type with complications. It was concluded that there was increased endothelium desquamation due to the VE-cadherin internalization at moderate and severe uncomplicated types of HFRS and as a result ofVE-cadherin gene c. 1550T>C missense mutation at severe type with complications.