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Based on the NCEP re analysis data, Doppler Radar products and FY satellite retrieval cloud parameters, the first snowfall process of 2009 in Tianjin area is analyzed. The research shows that: (1) The main synoptic systems caused this snowfall process were the eastward moving upper level trough and the surface inverted trough. (2) The snowfall echo showed the typical characteristics of stratiform cloud precipitation, with the echo intensity not exceeding 35 dBz, and at the ending of snowfall process, the echo top height descended. (3) The cloud particle effective radius maintained around 20 μm; during the snowfall process, the depth of supercooled cloud layer and cloud top height were larger, and the cloud top temperature was about -30 ℃; after the snowfall, the value of cloud particle effective radius, depth of supercooled cloud layer, and cloud top height decreased, while the value of cloud top temperature increased. (4) The correlativity between snowfall and cloud particle effective radius, depth of supercooled cloud layer, and cloud top height were positive, but that between cloud top temperature and snowfall was negative.