The present invention provides an image forming method including ejecting an ink composition, using an ink jet apparatus, onto a recording medium thereby forming an image, the ink composition comprising a pigment, a water-soluble polymerizable monomer which is polymerized by actinic energy rays, and water, and the recording medium being composed of a base paper, a first layer including a binder, and a second layer including a white pigment and an acidic substance, which are disposed in this order, wherein a surface of the first layer is disposed on the base paper and has a Cobb water absorption capacity of 2.0 g/m2 or less at a contact time of 120 seconds as measured by a water-absorbing capacity test according to JIS P8140, a surface of the second layer has a water absorption of from 2 ml/m2 to 8 ml/m2 at a contact time of 0.5 seconds as measured by the Bristow's method, and the surface of the second layer has a pH of 5.5 or less.