To clarify the motion and the disintegrating condition of liquid sheets quantitatively, contact frequency and contacting ratio were measured experimentally by the contact needle method. Then, three causes of disintegration were abstracted from them. Moreover, still photographs were taken along axial direction and analyzed to investigate the behavior of liquid lump from the breakup of a liquid film until the spray formation. Ligaments, filaments, non-spherical particles and spherical one were classified by geometrical parameters, area equivalent diameter d_ae, aspect ratio e and irregular ratio IR. As the results obtained under constant liquid velocity, the liquid sheet disintegrates with the pattern of "perforated sheet" when a thickness parameter is large, and there exists complicated-shaped particles originated by their disintegration pattern just after disintegration when a thickness parameter is small.