Abstract: Based on the Mie scattering theory, a formula to calculate the scattered light flux in a certain solid angle under the condition of polarized light input is derived form the formula for calculating scattered light intensity. The results are compared with the condition illuminated by a unpolarized light. The scattered light flux collected by the two common scattered light collecting systems of the airborne particle counter is calculated under the condition of different light sources but same light intensity. The result shows that the fluxe got by the nearforward scattered light collecting system is equal. On the contrary, with the right angle scattered light collecting system, they are not equal and with the lineary polarized light input, the collected light flux is related to the angle between the center of detector and the direction of polarization. Calculating results, based on MATLAB and worked out by the computer,indicate that the collected scattering light flux has extreme when the angle between the center of detector and the direction of polarization is 90°or 270°. The results may provide a reference for designing the transducer of airborne laser particle counter.