A method of preparing toner and a toner using the method is provided. More particularly, a method of preparing toner controls a shape of finally obtained toner particles by adjusting a molecular weight and Tg of polymer latex and can easily obtain a desired size, shape, and size distribution of toner particles by controlling aggregation of polymer latex particles and process conditions. A toner using the method, an image forming method using the toner and an image forming apparatus including the toner are also provided. The toner is prepared by forming polymer latex particles having different molecular weights by polymerizing a toner composition including macromonomers containing a hydrophilic group, a hydrophobic group and at least one reactive functional group, and at least one polymerizable monomer; and mixing the polymer latex particles having different molecular weights with a pigment dispersion solution to control aggregation of the polymer latex particles by controlling pH or an amount of added inorganic salts and optimizing process conditions.