OBJECTIVE: To develop a method for the determination of levodopa in human plasma and study aarodopa's pharmacokinetics. METHODS: Experiments were performed on Waters 2010 HIPLC system with a 474 fluorecence detector (?EX = 278nm, ?Em = 325nm) and a Lichrospher 100 C18 column. The mobile phase(pH3. 7) was 90% water containing 0.08 mmol/L EDTA, 70mmol/L KH2PO4, 2. 08mmol/L sodium heptanesulfonate and 10% methanal. The flow rate was 1. 0ml/min. The plasma sample was directly injected for determination after being deproteinized with perchloric acid. RESULTS: The linear range was 0. 125-4.0ug/ml,the limitation of detection was 0. 25ug/ml,within- day RSD