A field experiment of large scale snow storage was conducted in Sapporo. Objectives of this experiment are to experimentally verify that the storing snow with adding water is effective for snow compression and for making high density without any mechanical machines. Snow was stored in a large underground pit, which has a diameter of 1.0 m and 6.7 m deep with or without adding water. It was clarified that water addition to the stored snow is very effective to compress the shallow layer of the stored snow. In this time, water permeated through stored snow layer and fell down into the bottom space. It means that added water can be used repeatedly for the compression when water in the bottom space is pumped up. The observed maximum dry snow density was 582 kg/m^3.
