  We study the influences of antidot-induced bound states on transport
properties of two- dimensional quantum spin Hall insulators. The bound
statesare found able to induce quantum percolation in the originally insulating
bulk. At some critical antidot densities, the quantum spin Hall phase can be
completely destroyed due to the maximum quantum percolation. For systems with
periodic boundaries, the maximum quantum percolationbetween the bound states
creates intermediate extended states in the bulk which is originally gapped and
insulating. The antidot in- duced bound states plays the same role as the
magnetic field inthe quantum Hall effect, both makes electrons go into
cyclotron motions. We also draw an analogy between the quantum percolation
phenomena in this system and that in the network models of quantum Hall effect.
