PURPOSE: To provide an improved method for manufacturing a lithographic printing plate having a flexible carrier.

CONSTITUTION: An original including continuous gradations is screen-processed, and screen-processed data are obtained. A lithographic printing plate precursor is exposed like an image according to the screen-processed data. The lithographic printing plate is provided with a flexible carrier having a surface for discriminating an ink accepting part from an ink rebounding part at the time of this exposure like an image and arbitrary development. Then, the lithographic printing plate precursor exposed like an image obtained in this way is developed if necessary. In a method for manufacturing the lithographic printing plate from an the original including the continuous gradations constituted of several stages, the screen processing is a frequency modulation screen processing.