This Letter is concerned with the influence of polarization on the damage performance of type I doubler potassium dihydrogen phosphate crystals grown by the conventional growth method under 532 nm pulse irradiation. Pinpoint density (ppd) and the size distribution of pinpoints are extracted through light scattering pictures captured by microscope. The results show that the ppd of polarization that parallels the extraordinary axis is around 1.5× less than that of polarization that parallels the ordinary axis under the same fluence, although polarization has no influence on size distribution of pinpoints. We also find that the size distribution is independent of fluence, although the number of pinpoints grows with fluence.