An air pollution sampling system and a method thereof applied to a wide-area air sampling are revealed. Air is forced into an air sampling unit by movement of a vehicle, for performing an active air sampling without a power source. An air sampling unit includes a plurality of baffle plates so as to adjust air sampling rate and avoid interference caused by turbulence generated during the movement of the vehicle. A positioning device provides geographic coordinates, vehicle speed and time. An information processing device integrates sampling flow and positioning information from the positioning device, collects information generated by the sampling system, and computes statistics of the accumulated samples and relative sampling positions. By the collected sampling positions, time and flow rate, the sampling amount is obtained through data processing and calculation. In combination with the display of positioning data, the geographic area represented by the air samples could be understood more clearly.