Abstract: A calibration method for amplitude error of 1 bit digital synthetic aperture radiometry is given, which computes noise temperature using correlator＇s output by the injection of correlated noise, then calibrate the amplitude decrease of the correlation coefficient between channels caused by uncorrelated receiver noise. The method avoids the power measure suit （PMS） which using in traditional method, and simplifies the system. The analysis results show the method＇s calibration accuracy is not worse than tradition PMS＇s.