Abstract: The stability for linear continuous-time descriptor systems with an interval matrix was studied. Using Gershgorin's theorem, a sufficient condition was derived to judge a descriptor interval system to be regular, impulse-free and stable with the constraint that all the main-diagonal values of the system matrix A arc negative. Nevertheless, the sufficient condition was further developed to fit the case that the radius of the Gershgorin disc is comparatively large. Two examples were used to illustrate the validity of the method. And a necessary and sufficient condition is suggested to determine an interval matrix to be nonsingular.