A flow injection microsample introduction system for flame atomic absorption spectrom-etry is developed based on air-transported sample loading and hydrodynamic injection. An augmenting water stream was used between sample loop and nebulizer to prevent distur-bances from nebulizer suction during sample loading. A total of 0.8ml of sample was sufficient for triplicate measurements, including washout between samples, and achieving the sensitivity of conventional steady-state measurements. The system was applied to the determination of copper in serum samples at a sampling frequency of 100/h and with a presision of about 2% rsd.