  We study anisotropic magnetoresistance (AMR) in a spin-polarized
two-dimensional electron gas with Rashba spin-orbit coupling and nonmagnetic
disorder collision. We show that AMR exists, arising from the combined effect
of in-plane magnetization, spin-orbit coupling, and nonmagnetic remote disorder
scattering. Further, numerical evaluation demonstrates that the smoothness of
the remote disorder can strongly affect AMR, and this AMR is sensitive to the
electron density. Large magnitude of AMR ($\approx24%$) is obtained for low
density system with strong spin-orbit splitting.
