A method for preparing a lithographic printing plate, the method comprising: exposing imagewise a lithographic printing plate precursor comprising a hydrophilic support having provided thereon a photosensitive layer containing a hexaarylbisimidazole compound, a polymerizable compound containing a hydrocarbon group having 6 or more carbon atoms in its molecule, a sensitizing dye and a binder polymer, and a protective layer in this order using a laser; and removing the protective layer and an unexposed area of the photosensitive layer of the exposed lithographic printing plate precursor using a processing solution which has a pH in the range of 2 to 11, contains a compound represented by the following formula (II-1) or formula (II-2), and contains a compound represented by the following formula: wherein R 6 represents a k-valent straight-chain, branched or cyclic aliphatic hydrocarbon group having from 1 to 8 carbon atoms, which may have one or more hydroxy group(s) as a substituent, R 7 represents an alkyl group having from 1 to 9 carbon atoms or an alkenyl group having from 2 to 9 carbon atoms, which may have one or more hydroxy group(s), alkoxy group(s) or alkoxycarbonyl group(s) as a substituent, R 6 and R 7 may be combined with each other to form a ring, provided that a total number of carbon atoms included in R 6 and R 7 is from 5 to 25, and k represents an integer of 1 to 4; wherein R 4 represents an alkyl group having from 1 to 4 carbon atoms or an alkenyl group having from 2 to 4 carbon atoms, R 5 represents an alkyl group having from 1 to 9 carbon atoms, an alkenyl group having from 2 to 9 carbon atoms or an organic group containing an alkoxyalkylene group having from 2 to 9 carbon atoms, R 4 and R 5 may be combined with each other to form a ring, provided that a total number of carbon atoms included in R 4 and R 5 is from 5 to 25; wherein A represents an aromatic ring; R 8 represents an alkyl group having from 1 to 3 carbon atoms; L 2 represents a single bond or an alkylene group having from 1 to 4 carbon atoms; R 9 represents an alkylene group having from 1 to 4 carbon atoms; R 10 represents a hydroxy group, an alkoxy group having from 1 to 4 carbon atoms, a phenoxy group or a naphthoxy group; m represents an integer of 0 to 4; q represents an integer of 0 to 5; and n represents an integer of 1 to 8, provided that q and n satisfy 1 ≤ q + n ≤ 8. exposing imagewise a lithographic printing plate precursor comprising a hydrophilic support having provided thereon a photosensitive layer containing a hexaarylbisimidazole compound, a polymerizable compound containing a hydrocarbon group having 6 or more carbon atoms in its molecule, a sensitizing dye and a binder polymer, and a protective layer in this order using a laser; and removing the protective layer and an unexposed area of the photosensitive layer of the exposed lithographic printing plate precursor using a processing solution which has a pH in the range of 2 to 11, contains a compound represented by the following formula (II-1) or formula (II-2), and contains a compound represented by the following formula: wherein R 6 represents a k-valent straight-chain, branched or cyclic aliphatic hydrocarbon group having from 1 to 8 carbon atoms, which may have one or more hydroxy group(s) as a substituent, R 7 represents an alkyl group having from 1 to 9 carbon atoms or an alkenyl group having from 2 to 9 carbon atoms, which may have one or more hydroxy group(s), alkoxy group(s) or alkoxycarbonyl group(s) as a substituent, R 6 and R 7 may be combined with each other to form a ring, provided that a total number of carbon atoms included in R 6 and R 7 is from 5 to 25, and k represents an integer of 1 to 4; wherein R 4 represents an alkyl group having from 1 to 4 carbon atoms or an alkenyl group having from 2 to 4 carbon atoms, R 5 represents an alkyl group having from 1 to 9 carbon atoms, an alkenyl group having from 2 to 9 carbon atoms or an organic group containing an alkoxyalkylene group having from 2 to 9 carbon atoms, R 4 and R 5 may be combined with each other to form a ring, provided that a total number of carbon atoms included in R 4 and R 5 is from 5 to 25; wherein A represents an aromatic ring; R 8 represents an alkyl group having from 1 to 3 carbon atoms; L 2 represents a single bond or an alkylene group having from 1 to 4 carbon atoms; R 9 represents an alkylene group having from 1 to 4 carbon atoms; R 10 represents a hydroxy group, an alkoxy group having from 1 to 4 carbon atoms, a phenoxy group or a naphthoxy group; m represents an integer of 0 to 4; q represents an integer of 0 to 5; and n represents an integer of 1 to 8, provided that q and n satisfy 1 ≤ q + n ≤ 8.