Spectral radiance of infrared targets are widely used in weapon photoelectric search, track and identify targets. Based on infrared radiate theory, the technologies of Fourier transform infrared spectroscopy(FTIR) and comparing with standard blackbody source were used to measure spectral radiance of infrared targets at the same temperature and wavelength. The spectral radiance measurement system of infrared targets was also built. According to the results, it is shown that the measurement error is±1% at 1 000 ℃, 3 000 ℃, 5 000 ℃, 7 000 ℃ temperature point and the measurement error is less than 0.1% at 5 000 ℃, 7 000 ℃ temperature point at the range of 2.5-14 μm. Some factors that affect the measurement accuracy of the infrared spectral radiance were analyzed and discussed. It is obtained that the measurement error is greater when the standard black body temperature is inconsistent with the infrared target temperature; the measurement deviation is ±0.5% with InSb and MCT detector respectively at the range of 3.0-5.4 μm.