An image forming method of the present invention including applying a pretreatment liquid to a recording medium, and discharging an inkjet recording ink dropwise according to an image signal to form an image on the recording medium on which the pretreatment liquid has been applied, wherein the recording medium is regular paper which has no coat layer, the pretreatment liquid contains a cationic polymer compound, a surfactant A, water and a water-soluble organic acid, and the inkjet recording ink contains a water-dispersible colorant, a water-soluble organic solvent, a surfactant B, a penetrating agent and water, and wherein the pretreatment liquid has a static surface tension of 20 mN / m to 30 mN / m.