The development of integral radiometer is discussed. At the base of Mark II spectral radiometer, the integral radiometer was newly designed and debugged in optical system, infrared detector, electronic circuitry, mechanical equipment and control software. With the reconstruction, the new integral radiometer can measure the infrared radiation within the wave band of 1~3μm?3~5μm?8~12μm. The repeatability, stability and accuracy of the radiometer by measuring and demarcating with the normal blackbody are valid...