Radiation-sensitive composition, planographic printing plate precursor, and plate-making method for planographic printing plate

A planographic printing plate precursor for on-press development, comprising:

• a support;
• and
• an image recording layer which comprises a radical initiator, a radical polymerizable component, and a radiation absorption compound, and wherein the image recording layer shows two or more peaks of a radical generation amount in a radical generation amount-versus-time curve after exposure to image forming radiation,
• the radiation absorption compound comprising a compound represented by the following Formula 1:
• wherein, in Formula 1, R1 represents a group capable of cleaving R1—X bond due to exposure to image forming radiation, X represents —NRN—, RN represents an alkyl group, R2 and R3 each independently represent a hydrogen atom or an alkyl group, R2 and R3 may be linked to each other to form a ring, Ar1 and Ar2 each independently represent a group forming a benzene ring or a group forming a naphthalene ring, Y1 and Y2 each independently represent an oxygen atom, a sulfur atom, —NR0—, or a dialkylmethylene group, R4 and R5 each independently represent an alkyl group, R6 to R9 each independently represent a hydrogen atom or an alkyl group, R0 represents a hydrogen atom, an alkyl group, or an aryl group, and Za represents a counter ion that neutralizes the charge.