The Alpha Magnetic Spectrometer (AMS) is a high energy physics experiment designed to study origin and nature of cosmic rays (CRs) up to TeV energies from space. AMS was installed on the International Space Station (ISS) on May 19th, 2011. With its high sensitivity, long exposure and excellent identification capabilities, AMS is conducting a unique mission of fundamental physics research in space. To date, more than 50 billion CR events have been collected by AMS. Along with an overview of the AMS physics program, recent results on CR measurements will be presented, with particular emphasis on the preliminary data on CR proton, helium, and light-nuclei fluxes. The interpretation of these new data in the context of Galactic propagation models will also be discussed.
