Abstract: Before M_L7.6 earthquake occurred in Nantou on September 21, 1999, an earthquake belt phenomenon occurred in Taiwan Island. Here, the seismic pattern before M_L7.0 earthquake in Taitung overseas on Dec. 2004, M_L7.2 earthquake in Kaohsiung overseas on Dec.2006 and M_L6.7 earthquake in Kaohsiung on Feb.2016 is restudied with earthquake belt method in this paper. The result showed that the earthquake belt phenomenon M_L>5.5 had occurred before the three earthquakes mentioned above. It explains that there had existed all earthquake belts before strong earthquake in Taiwan Island and its adjacent waters in recent years. After analyzing the forming cause of these earthquake belts, we consider that the earthquake belt of N-E direction is formed by Philippine plate squeezing. The earthquake belt along the eastern coast of the Taiwan island is formed by seismic fault effect on the east Taiwan island. The earthquake belt along the Ryukyu trench is formed due to the Ryukyu trench fault zone. The result has referent significance for earthquake prediction on the Taiwan Island and its adjacent sea area.