The present paper describes the results of observation on the behaviour of a sectional snow cloud at Yonezawa by a Mie scattering laser radar. Laserradar offers the measurement of the phase of a cloud to a certain extent by using the depolarization property of backward scattering light. The present laser radar has two receiving channels for measuring vertically and horizontally polarized signals simultaneously. During the observation there was once a heavy snow fall which continued until the following day, besides several intermittent snow falls. From the observation of continuous snow, the most significant behavior of the cloud before the snow fall was that the ceiling height decreased gradually, after the ice-crystal cloud of the upper layer had changed to snow-flake cloud. For intermittent snow, the variation in the height of the clouds was much more prominent than in the case of continuous snow.
