Centrifuge modeling of rainfall induced failure of layered soil slope consisting of sand and clay layers was achieved to study the deformation, failure and suction change patterns of such slopes during rainfall. Retrogressive failure in the slope was observed during the experiment. Analysis on the deformation characteristics of the slope showed that the shear zone was more concentrated in the sand zone than in clay, and the sliding surface in the sand layer developed outside the shear zone due to the deformation in the clay layer. Though soil suction in both layers exhibited significant decrease during rainfall, the decrease occurred much earlier and faster in the sand layer. Suction decrease and strain increase occurred simultaneously in the clay layer but not in the sand layer.