In this study, we classified the types of west coastal snowfall of the Korean peninsular from November 2015 to February 2016. Three dimensional structures of the snowfall in synoptic- and meso-scales are analyzed and penetration of the snowfall into the land is studied. Sensitivity experiments for sea surface temperature (SST) are conducted to reveal impacts of air-sea temperature differences and land-sea temperature contrast on the snowfall. The types of west coastal snowfall were divided into the Honam area type, the Central area type and the Honam coastal type using the 24h accumulated precipitation amount data of AWS. Common characteristics of the west coastal snowfall are located expanded Siberia high pressure on the South China region and Korean peninsular is affected to low pressure system. Then cold advection because of the distribution of atmospheric pressure is occurred and pressure gradient became strong and wind speed in west sea of Korean peninsular became strong too. Middle level is helped system development. Honam area type was developed low pressure to east sea then was influenced in Korean peninsular. Central area type was affected a low pressure with a cold front. Honam coastal type is was expanded Aleutian low pressure system then influenced in Korean peninsular. The sensitivity test was conducted by selecting the case of the Honam coastal type. As a result, the higher the SST is the stronger the strength of the snowfall and the faster the snowfall time. The other way, the lower the SST is the weaker the snowfall and the slower the snowfall time. This indicates that the density wall due to the temperature difference between sea and land in the lower atmosphere determines the west coastal snowfall. The west coastal snowfall is a meso-scale weather phenomenon, but it is confirmed that the influence of the distribution of atmospheric pressure of the synoptic scale and the influence of the middle level are the main factors. Cause in meddle level is changed the air because of meeting the warm extremity of the sea and the cold extremity of the land. Trough sensitivity experiment, it was confirmed that the location and timing of the snowfall change according to the influence of the SST as well as the distribution of atmospheric pressure of the synoptic scale.