InordertoevaluatetheimagingqualityofCCDcamerasfullyandrapidly,theminimumresolvablecontrast(MRC)ispresentedinthispaperandthesystemofmeasuringMRCisconstructedaswell,inwhichtwointegratingspheresareproposedtoilluminatetwosidesofthetargetrespectively.Thevariablecontrastcanbeobtainedbyregulatingtheluminanceofintegratingspheres.Experimentalresultsindicatethattheerrorofmeasuringluminanceiswithin±0.3cd/m2,MRCriseswiththeincreaseofthespatialfrequency.TheexperimentalresultsshowthatthemethodproposedisaneffectiveapproachtoevaluatetheimagingqualityofCCDcameras.