PURPOSE: To obtain an image forming method capable of forming images free from unequal densities by forming the test images, measuring the optical densities of these test images and forming the images by correcting the energy of exposure in accordance with the results of the measurement of the optical densities.

CONSTITUTION: A thermodevelopment type photoreceptor is exposed with uniform intensity and is further heated, by which the test images a1 to a a25 are formed. These test images a1 to a25 are ideally free from unequalness in the optical densities. However, the unequal densities of the test images a1 to a25 are usually generated by a factor, such as changing of the heating temp., at the time of the thermodevelopment. The unequal densities are, therefore, detected by measuring the optical densities of the test images a1 to a25 with a densitometer. Next, the exposure intensity of a light source is corrected by the detected unequal densities and the desirable images free from the unequal densities are formed. Namely, the exposure energy is increased in the parts where lowering of the optical densities is expected by the detected unequal densities. Conversely, the exposure energy is decreased in the parts where increasing of the optical densities is expected.