Abstract: The Jiufengershan landslide with the volume of 4107m3 is one of the huge landslides induced by the 1999 Taiwan Chi-Chi Earthquake. The collapse mechanism of this landslide may be shear out or buckling, which is an argument need to be further. This paper demonstrates that there might be different failure mechanisms that could happen in the landslide block at a reasonable friction coefficient of 0.05 by the 3-D models. Taking toe particles into account, the collapse mechanism is dominated by buckling with short run-out distance in the southern section. On the other hand, the mechanism is dominated by shear out with long run-out distance in the northern section. Thus, the mechanisms of large landslides are probably not unitary, and complex failure mechanisms might be existed due to the complex topographic features. Our result suggests that, in addition to the property of the landslide and the tectonics, the geomorphologic conditions and the geometric features of the landslide face can also play an important role in the occurrence and landsliding process of earthquake-triggered landslide.