AMS (Alpha Magnetic Spectrometer) is a space-born experiment to search for dark matter and antimatter. The AMS detector had a precursor flight in 1998 (STS91, June 2-12, 1998). The final detector (AMS-02) will be installed on the International Space Station (ISS) in the beginning of 2008 for at least three consecutive years [1]. This paper gives an overview of the AMS Ground Data Handling System emphasizing the distributed data processing based on a client/server approach. We also present several data transfer tests that have been made between CERN (Geneva, Switzerland) and AMS remote centers in Europe, USA and Asia.