A new variable energy (200 -1000 MeV) proton beam line at 1 GeV PNPI synchrocyclotron has been completed. The energy variation of the beam is provided by the copper degrader. Monte Carlo simulations of the beam propagation in the degrader as well as in the magneto-optics channel have been performed. Good agreement between theoretical calculations and experimental data is obtained. 0-7803-8127-0/03/$17.00 (C) 2003 IEEE