Fukui Prefecture faces Japan Sea and receives air pollution from China mainland. China shows more than 10% per year of high economic growth and uses coals with high sulfur content as main resources of energy. It is afraid that Fukui would receive severe damage by acid deposition in the future. Air which arrives at Fukui is simulated by inverse trajectory analysis. Air at Fukui arrives from China mainland from October to April, and from Pacific Ocean in July and August. Other months are transient of winter and summer season, air comes from almost all direction.
