A special feature of building design is the external forces imposed on structures. In the Kobe Earthquake, which occurred on January 17, 1995, a maximum acceleration of 818cm/s2 was recorded, and fatalities numbered 6,432. Typhoon No.19 in 1991 made a landfall on September 27 and traveled through the Japanese islands. New wind speed records were registered at various weather stations, e.g. maximum peak gusts of 88.8m/s and 58.1m/s were recorded at Shimokoshiki Island and Hiroshima City, respectively. It caused severe damage to buildings, power transmission towers, agricultural and forestry areas, etc., and property insurance of 5 billion USD was paid out. This was a world record for insurance money paid out for one natural disaster at that time. Tall buildings in Japan have to resist two different kinds of extreme design forces. More recently, Typhoon No.14 attacked southern part of Japan on September 11, 2003, and a maximum peak gust of 74.1m/s was officially recorded at the meteorological station on Miyakojima Island. It is interesting that an anemometer at an experimental site for power transmission cables on the Miyakajima Island recorded a peak gust of 96m/s, and the calibration of this anemometer is now being checked to ensure that this reading is correct. The special feature of building design in Japan is that they need to resist extremely strong winds and earthquakes. It is well known that light, flexible buildings are favorable for resisting seismic forces, while heavy, stiff buildings are favorable for resisting wind forces. Thus, tall buildings in Japan have to satisfy these two opposite design criteria, and this is one of the most difficult design issues for tall buildings in Japan. In addition, there are many important issues to be solved in the design stage, the construction stage, and even in the maintenance stage after completion of a tall building. Many wind engineers have devoted themselves to finding solutions to these issues, and to exploring new methods and technologies.