The knowledge of the particle shape and motion characteristics in a pan coater is critical to optimize the design and operation of coating equipment. To research the influence of tablet shape on the motion characteristics in a coating device, which based on discrete element method and spray zone approach, the motion characteristics of tablet particles with five shapes including rod, long ellipsoid, oblate ellipsoid, biconvex and spherical was investigated by numerical simulation. Inter-tablet variability of film coating was a critical issue in the production of solid oral dosage forms. Residence time distribution and it's relative standard deviation was developed to characterize the coating process throughout the coating vessel. The effect of tablet shape on energy of granular system, surface particles translational velocity, granular temperatures, residence time distribution and it's relative standard deviation was investigated systematically. The results showed that tablet shape significantly affected the kinetic energy of granular system, particle translational velocity, granular temperatures, residence time distribution and inter-tablet coating variability. Except for the biconvex granular system, the kinetic energy, bed translational velocity and granular temperatures of the other four kinds of granular system decreased with the increasing sphericity. Residence time distribution of the granular system gradually became normal. Weight gain mass coating variability (CVm) was to be inversely proportional to the square root of coating time and in good agreement with the Chang and Leoni experimental results. Except for the rod-shaped granular system, there was a decrease in the average residence time of the granular system in the coating spray area, an increase in the relative standard deviation of the average residence time with the increasing sphericity. Meanwhile, the inter-tablet coating variability also deteriorated. Compared with the spherical granular system, the inter-tablet coating variability of non spherical granular system showed a better behavior.