Based on the Micaps meteorology data provided by China Meteorological Administration, the source, movement route, influence areas and impact probabilities on different seas were studied for each case. It was shown that about 70% sand-dust storms that influenced China originally came from Mongolia, and were strengthened during their movement in the desert areas of China. There were totally 42 sand-dust storms influencing China and three movement routes from west to east during 2000-2002. Firstly, sand-dust originally occurred in Mongolia intruded into China from the east part of Inner Mongolia, by the way of Hunshandake desert and Horqin desert, and were deposited into the Bohai sea, the Yellow sea, Korea Strait and Japan sea; secondly, sand-dust coming from Mongolia intruded into China from the west of Inner Mongolia, were transported from west to east, and then sunk into the Bohai sea, the Yellow sea, the East China sea, Korea Strait and Japan Sea; and thirdly, sand-dust that occurred in Mongolia and in the northwest of China were transported by the high northwest current and sunk into the Yellow sea, the East China sea and the West Pacific Ocean. There were about 63.9% sand dust weather that might affect China seas by the three different routes. The impact probability on the Bohai sea was 27.4%, the Yellow sea 30.9%, the East China sea 12.3%, Korea Channel 20.2% and Japan sea 9.2%.