In this paper

a algorithm of region-based 3D motion tracking on multi-linkage is proposed. Firstly based on the fact that the length of fingers is same in motion

and each of them lies in the same virtual plane because of only one degree of freedom at their joints

which is defined as the rigidity constraint and complanar constraints respectively

we obtain the initial 3D structure of finger from the image by exploiting these constraints and special properties on fingers. Then by the motion properties of rigidity multi-linkage and corresponding gesture constraints

we give the general descriptions of 3D region tracking of the linkage. Finally we apply the techniques to 3D motion tracking of hand. Here genetic algorithm is employed to our optimal iteration. In order to verify the validity of our approach

we use 3D motion of fingers

which is obtained from the real image sequence

to drive our virtual model of fingers. The results demonstrate the validity of the method.