The objective of this study was to evaluate the in vivo characteristics of poly (ethylene glycol)-poly (lacticacid-co-glycolicacid)-poly (ethylene- glycol) (PELGE) copolymers as drug carriers. In order to test this circulation time, mitoxantrone (DHAQ) was used as a model drug in this study. DHAQ nanoparticles (DHAQ-NP) were prepared, subsequently the DHAQ-NP were evaluated by measuring the drug concentration in plasma after intravenous administration via the tail vein of mice. The circulation time of the DHAQ-NP were tested. The results showed prolonged mitoxantrone (DHAQ) residence in systemic blood circulation.