To clarify the wave properties at different locations in the Beaufort-Mackenzie Sea area when sea ice varied significantly under violent storm condition, based on the observed winds, waves and daily sea ice data of one of northwest arctic storm (Oct. 5-8, 2008) during open water season in the Beaufort-Mackenzie Sea area, changes of sea ice concentration, developing stage and sea ice size are studied. Waves are simulated with SWAN model under dramatic variations of wind velocity, wind direction and sea ice during the storm, and comparison study is also carried out between model simulations with sea ice mode covering realistic sea ice information(sea ice concentration, development stage and size information) and different sea ice concentrations as model boundary. The results show that reasonable simulation results are obtained in areas off sea ice cover region by using the two sea ice modes; sea ice mode covering realistic sea ice information gives more precise waves simulation results during storm. Simulation with sea ice mode covering realistic sea ice information indicates that dramatic changes of wind velocity, wind direction and sea ice induce severe variations of wave strength and distribution in Beaufort-Mackenzie region, the most violent waves occur at the biggest wind time.