All investigation on the seismic behaviors of crane structures was conducted following the collapse of two tower cranes during the construction of the 101-story Taipei financial Center in the 2002 Hualien(331) Earthquake originated 44 kilometers off the east coast of Taiwan. Analysis was carried out on computer models representing various construction stages of typical tall building structure through both response spectrum and time-history analyses to estimate the possible seismic load that would be inflicted on the crane structure. A comparison was made between results of these two approaches to verify that whether the spectrum analysis is able to yield an accurate result based on acceleration record obtained at the location where the crane was mounted. The result of this analysis showed that in the absence of eccentricity, the spectrum method was able to produce satisfactory results while requiring minimal calculation. However, if the crane was allocated away from the center of rigidity, a twisting motion may take over the vibration of building, which would affect the accuracy of the spectrum method.