To understand the movement of solid particles in micro-channel and improve the anti-clogging ability of emitters,we observed the movement of solid particles of different diameters and the different densities in labyrinth channel using particle image velocimetry(PIV).The trajectories of solid particles showed that water in zigzagging channel flew in sine wave,and formed mainstreams near the tips of the spikes and turbulence at the bottoms.Particles of small diameter(65 mm) or low density(1 740 kg/m3) exhibited apparent following behaviors.With the increase of the diameter or density,water flew more turbulently,particles moves slower and became more easily to be trapped and caused clogging.Comparing to the diameter,the density of the particles affected less their movement trajectories,path lengths and velocities.