  We study the nature of the disorder-induced quantized conductance, i.e., the
phenomena of topological Anderson insulator (TAI) induced in HgTe/CdTe
semiconductor quantum well. The disorder effect in several different systems
where anomalous Hall effect exist, is numerically studied using the
tight-binding Hamiltonian. It is found that the TAI phenomena also occur in the
modified Dirac model where the quadratic corrections $k^2\sigma_z$ is included
and electron-hole symmetry is kept. It also occurs in the graphene system with
the next nearest-neighbor coupling and staggered sublattice potential.
Comparison between the localization lengths of the 2D ribbon and 2D cylinder
clearly reveals the topological nature of this phenomena. Furthermore, analysis
on the local current density in anomalous quantum Hall systems where the TAI
phenomena can or can not arise reveals the nature of TAI phenomena: the bulk
state is killed drastically and only the robust edge state survives in a
moderate disorder. When the edge state is robust enough to resist the strong
disorder that can completely kills the bulk state, TAI phenomena arise.
