Lithographic printing plate precursor and method of preparing the same

A positive lithographic printing plate precursor with an infrared-sensitivity, having a support and an image recording layer provided on the support, the support having a hydrophilic surface, the recording layer comprising:

• a maleimide resin A;
• an amphoteric surfactant and/or an anionic surfactant;
• and
• an infrared absorbing agent;
• the maleimide resin A being a copolymer formed from monomers containing:
• methacrylic acid;
• at least one kind of compound selected from the group consisting of N-phenylmaleimide, N-cyclohexylmaleimide and N-benzylmaleimide;
• and
• a monomer having a structure represented by formula (A):
• wherein R21 represents a hydrogen atom or a methyl group;
• X represents an alkylene group having 2 to 12 carbon atoms, an oxyalkylene group having 4 to 8 carbon atoms or —SiRa2—;
• Ra represents an alkyl group and the two (2) alkyl groups represented by Ra may be the same as or different from each other;
• and m represents an integer of 1 to 3.