A bi-directional microfluid control system was developed either numerically and experimentally in this work. This pneumatic system is an on-chip planar structure without moving parts and does not require microfabricated heaters or electrodes. The pumping actuation is introduced to the microchannel fabricated in chip by blowing an airflow through this device. The tunable parameters for adjusting the performance of pumping were the location of the inlet channel and the velocities of the airflow. The driving module was fabricated on PMMA and its feasibility was examined experimentally. The droplet of water in the microchannel can move forward, backward and stop under control of this driving module. The driving system is therefore particularly suited to micro devices for biochemical analysis.