A method of preparing a toner is provided, including: polymerizing a toner composition including a chemically reformed or modified plant oil or a fatty acid, one or more polymerizable monomers, and a colorant with a free radical initiator; and separating and drying the polymerized toner. Also, provided are a toner prepared using the method, an image forming process using the toner, and an image forming apparatus employing the toner. According to the method, an environmentally friendly toner with superior durability and fixation properties is manufactured by using chemically reformed or modified plant oil or fatty acid. Also, regulating the size, the distribution and the configuration of toner particles are easy. In addition, the method does not involve the use or minimizes the use of a surfactant, thus decreasing the amounts of polluted water and waste water, which is very advantageous environmentally.