Abstract: In order to measure and analyze the noise performance of low-light-level imaging system separately from temporal and spatial field, 3-D noise models and their measurement system was established. The 3-D noises of both ICCD and CCD imaging system was measured by the system. Measurement results indicate that the spatial noise, temporal noise, signal average value and signal to noise ratio are increased with the increase of the cathode luminance of ICCD image intensifier, which accord with the performance of a real imaging system. The analysis of 3-D noise indicated that two kinds fixed pattern noise respectively formed by imaging plane defect and dead pixel dots were distinguished in ICCD or CCD imaging system and the qualitative evaluation was carried out to optical taper coupling technology.