This study aimed at elucidating the relationship between NTP apoptosis and endothelial cell injury. After isolation and purification, activated NTPs were incubated with endothelial cells directly or indirectly contact in a ratio of 5:1 and 10:1, meanwhile 10ng/ml IL-6 and 10% (v/v) burned serum added or not. Apoptosis and necrosis of endothelial cells were detected in situ. Activated NTP alone exerted no obviously detrimental effects on endothelial cells. However, when IL-6-or serum from burn patients was added, NTP apoptosis was delayed and endothelial cells were injured in the form of necrosis. Inflammatory mediators can delay NTP apoptosis, further research demonstrated that direct contact between the two types of cells was essential for NTP to impact injury on endothelial cells.