D0空间的像和原像

This paper is devoted to the images and preimages of D0 spaces.First of all,we prove that the preimage X of a D0 space Y under a perfect mapping f is a D0 space whenever X has a G^*-diagonal or every compact subset of Xif Gδ，And then we give a representation theorem of Dδ spaces.At last,we give a characterization of countably compact D0 spaces.