An information storage medium, a recording/reproducing apparatus and a recording/reproducing method are provided to increase data reproduction efficiency. The recording/reproducing apparatus includes: a write/read unit for recording data on an information storage medium and reading data from the medium; and a controller for controlling the write/read unit to record a replacement block by logical overwrite (LOW) for updating data recorded on the medium in a first area of the medium, record a replacement block for replacing a defect block generated on the medium in a second area of the medium, and record a second replacement block for replacement by defect of a first replacement block in the second area if the defect is detected while the first replacement block is being recorded in the first area to perform the logical overwrite of an original block recorded in a predetermined area of the medium, generate a defect list (DFL) entry including location information of the original block and location information of the second replacement block in order to indicate the replacement state, and move location information of the first replacement block in the second replacement block. As a result, an area for replacement by defect and an area for replacement by LOW are discriminated from each other, and data reproducing efficiency can be improved by effectively managing replacement information though the replacement by defect due to a defect generated during the replacement by LOW.