A system for correcting a charged particle beam lithography condition including: an error calculation unit configured to calculate an error in an illumination position of a charged particle beam, the charged particle beam is controlled by a lithography condition corrected by initial correction parameters; a temporary correction unit configured to calculate temporary correction parameters to decrease the error to a minimum; and a main correction unit configured to calculate main correction parameters correcting the lithography condition, by executing statistical processing using the temporary correction parameters and the initial correction parameters.