Ni–ZrO 2 functionally graded materials (FGMs) have been fabricated via slip casting under a series of gradient magnetic fields. The effects of field gradient, holding time and Ni concentration on microstructures of Ni–ZrO 2 FGMs were investigated. A Ni composition gradient was formed along the field direction in Ni–ZrO 2 FGMs, and increased when the magnetic field gradient increased from 0.5 to 3.0T/m. Moreover, the composition gradient also increased with the prolongation of holding time. However, the composition gradient decreased as Ni concentration increased from 4 to 15wt.%, which can be attributed mainly to the formation of Ni clusters. A schematic model was proposed to explain the distribution of particles in gradient magnetic fields.