Objective    To prepare ADM-PLGA nanospheres (ADM-PLGA-Ns) and investigate their general characteristics

drug release characteristics in vitro.     Methods    The ADM-PLGA-Ns were prepared by W/O/W multiple emulsion volatilizing method. Their general properties were observed. HPLC was used to measure the content of ADM. In vivo conditions were simulated to study ADM-PLGA-Ns release characteristics.     Results    The ADM-PLGA-Ns were even and uniform spheres with mean particle size of (21±5.4) nm in diameter. The drug loading amount and encapsulation efficiency of ADM-PLGA-Ns were (89.71±7.31)% and (0.75±0.54)% respectively. The in vitro release profile of ADM-PLGA-Ns was figured by Higuichi equation. The drug release reached 95.00％ at the 10th day.      Conclusion    The prepared ADM-PLGA-Ns have good properties including sustained release in vitro.