The particle extinction characteristics, determined by receiption in short distance, is discussed. Calculations show that the extinction coefficient in short distance, especially for the large particles, is very different from that in long distance, i.e. it is not only dependent on particle properties, but also the location of particle in measuring beam. Therefore, the above mentioned factors should be taken into account when the short distance receiption is used to measure the particle size. Furthermore, the way to define the measurement volume under the receiption in short distance is also described, the particle diameter and concentration can be clearly determined by above mentioned method.