  We use the string melting version of a multi-phase transport (AMPT) model to
study Cu+Au collisions at $\sqrt{s_{NN}}=200$ GeV. The rapidity distributions
of identified hadrons show asymmetric dependences on rapidity. In addition,
elliptic and triangular flows at mid-rapidity from the AMPT model for pions,
kaons, and protons agree reasonably with the experimental data up to
$p_{T}\sim1$ GeV$/c$. We then investigate the forward/backward asymmetry of
$v_2$ and $v_3$. We find that these anisotropic flows are larger on the
Au-going side than the Cu-going side, while the asymmetry tends to go away in
very peripheral collisions. We also make predictions on transverse momentum
spectra of identified hadrons and longitudinal decorrelations of charged
particles, where the average decorrelation of elliptic flow in asymmetric Cu+Au
collisions is found to be stronger than that in Au+Au collisions.
