Abstract: Parallel mechanisms have multiple forward kinematic configurations,and we analyze the non-singular paths between different configurations with a 3-DOF planar parallel mechanism as an example.With the first path discovered by Innocenti, the distribution of these configurations in the workspace is analyzed based on graphic mode of singular surface.A lot of paths are found between these two configurations and these paths form a helix-like piping region.It first claims that there also exist another two configurations with this kind of paths.The results show that the distribution of singular surface and forward kinematic configurations of parallel mechanisms is very complex.If two configurations have opposite determinant sign of Jacobian matrix,there mustn’t have non-singular paths,while for the same sign,it should also be decided according to singular surfaces.The decision rule of non-singular path existence between two forward kinematic configurations depends on more clear discription of singular surface eventually.