The present invention relates to a negatively chargeable toner, comprising: toner particles prepared by means of a wet granulation method; and external additives externally added to the toner particles, wherein the external additives comprises a first hydrophobic silica having a mean primary particle size of 5 nm to 18 nm, a second hydrophobic silica having a mean primary particle size of 18 nm to 50 nm, which is greater than that of the first hydrophobic silica, and a hydrophobic titanium oxide having a mean primary particle size of 10 nm to 40 nm, and a full color image-forming method using the negatively chargeable toner.