The precipitation processes was investigated as typhoon Nari landfalling Taiwan during 16~23 Sep 2001. Typhoon Nari affected Taiwan lasted for 49 hours with the unique track as show in the figure. Many stations measured the recorded daily rainfall. Primary studies showed that two distinct precipitation events were occurred during the landfalling period. The landfalling process caused the heavy precipitations in the first 16 hours. During the next 24 hours, a stationary squall-type spiral rainband was formed around northern Taiwan as show in the figure. The further analysis included the dual-Doppler radar and surface analyses are performed to figure out the mesoscale structures and the maintenance mechanism for the stationary squall-type spiral rainband.