A developing agent is used for a recycle type image forming apparatus including an image bearing body on which an electrostatic latent image is developed with the developing agent and an image transferred to a transfer medium is formed, and includes a toner particle, a magnetic carrier to charge the toner particle to a specified polarity, and a circulation agent which is charged to a polarity reverse to that of the toner particle in the developing agent, has a primary particle diameter of 20 to 100 .mu.m, has a magnetization lower than that of the magnetic carrier, and has a transfer efficiency of 0 to 10% from the image bearing body to the transfer medium.