Abstract: In this work, the influences of the initial release angle on the motion of a two-dimensional flat plate falling freely in a fluid are investigated, using an immersed boundary method named by the local DFD (Domain-Free Discretization). Some interesting results have been obtained. At higher Reynolds numbers, for the plates with small moment of inertia, the release angle has no influence on the final motion, which exhibits a periodic fluttering. For the plates with mediate moment of inertia, the release angle influences the plate motion, the falling of the plates changes from tumbling mode to the chaotic motion as release angle increases. For plates with larger moments of inertia, the release angle again has no influence on the final motion, and the plates eventually settles into the periodic tumbling. At lower Reynolds number, the release angle influences the motion of plates with large moment of inertia. When the release angle is small, the plate motion exhibits a stable falling or a fluttering with small amplitude. As the release angle increases, the plate motions transition to the tumbling mode. The mechanisms responsible for the changes in the modes of plate motion have also been analyzed and discussed.