The Fermilab Main Injector is a rapid cycling proton synchrotron. It is designed to accelerate protons and antiprotons to 150GeV. The initial commissioning phase was in the summer of 1999. Since then, Main Injector has been supporting the high energy physics program at Fermilab. Beam studies for continued improvements in machine performance are in progress, in order to support a luminosity of 8*10 31 cm -2 sec -1 during Run IIa. The status of the Main Injector and beam studies results are presented.