A temperature control system and method for devices under test and an image sensor-testing apparatus having the system are provided. The temperature control method for devices under test mainly comprises the steps of regulating the temperatures of a plurality of devices under test (DUTs) to a specific temperature in a temperature control zone; transferring the plurality of devices under test to a test plate and placing them into a plurality of test slots respectively; and measuring the temperatures of the device under test by the temperature-sensing elements in the test slots, wherein when at least one temperature-sensing element of the temperature-sensing elements detects that the device under test in the test slot corresponding to said at least one temperature-sensing element fails to meet the specific temperature, a temperature control element corresponding to the test slot regulates the temperature of the device under test.