Optical information recording/reproducing method

An optical information recording/reproducing method for recording n-level multilevel information on an optical information recording medium with a track by forming information pits of various areas or various widths in the track direction so as to cause a reproduced signal having a multilevel amplitude to be generated, the information pits being formed on respective cells of the same width virtually provided on the track, and/or reproducing the n-level multilevel information from the optical information recording medium, the method comprising the steps of:

• obtaining in advance, in three consecutive cells consisting of a preceding cell, a center cell, and a subsequent cell, a possible change rate of an amplitude of the reproduced signal for the center cell with respect to a sum of multiple values of the preceding and subsequent cells;
• obtaining the sum of multiple values of adjacent preceding and subsequent cells with respect to each cell for reproduction;
• correcting the amplitude of the reproduced signal obtained at the center cell to be closer to a reference value on the basis of the obtained change rate and sum;
• and
• reproducing the multilevel information on the basis of the corrected amplitude of the reproduced signal.