The ow of uids including micron Particles in micro channels and manufacturing micro uidics tools have been one of the important topics in last decades and are utilized in di erent industries. The research procedure is experimental in this work. The experimental tests are carried out on the ow in a convergent-divergent microchannel having 200 m height. The utilized experimental method in this research is particle tracking based on the xerography technique, observation, record and data processing. The results showed that the velocity of the Particles in Y-direction has a great e ect on their motion in the convergent-divergent channel. Study of the Particles' sedimentation in di erent Reynolds showed that it can be eliminated the destructive e ect of channel obstruction using convergent-divergent channel which is originated from increasing sedimentation in low Reynolds. The shear stress and velocity gradient are two main factors of the Particles' velocity in the convergent-divergent channel. The results showed that the shear stress has an excessive impact on the Particles' velocity than the velocity gradient. Moreover, besides the upper and bottom walls, side walls a ect the Particles' velocity.