Abstract: The present invention relates to a negative photosensitive composition comprising: (A) an infrared absorber, (B) an organic boron compound which has a function as a polymerization initiator when used in combination with the infrared absorber (A), (C) an onium salt, and (D) a compound having a polymerizable unsaturated group. The use of the negative photosensitive composition of the present invention makes it possible to provide a negative photosensitive composition which is curable by infrared light and is less likely to cause polymerization inhibition due to oxygen during radical polymerization, and is also excellent in storage stability, and to provide a negative photosensitive lithographic printing plate which can directly form images by irradiation with infrared light from a solid laser or a semiconductor laser based on digital signals without preheating and shows high sensitivity, and is also excellent in printing durability and storage stability.