The two-dimensional distribution of liquid flow is measured in a gas-liquid concurrent downflow trickle bed, where trilobe particles are packed with three different methods, i.e. random, convex and concave packing. The effects of shape and orientation of particles on the liquid flow rate distribution are examined. The particle orientation has a significant effect on the liquid flow in the trickle bed. The liquid is distributed toward the wall when the trilobe particles are packed in the convex structure, but is converged into the tenter of the bed packed in the concave structure.