Abstract: Dry mycelium of Penicillium chrysogenum (DMP) could protect plant from disease. But its mechanism of induction and signaling pathways was unclear. Analyzing the genes expression in the plant treated by DMP was a good way to find out how inducing agent works. SSH technology was used to establish a cDNA library of tobacco induced by Dry mycelium of Penicillium chrysogenum. In the library 356 positive clones were obtained, of which 102 clones were selected for sequencing and 77 were sequenced successful. The result of Blastn showed that 47 genes' functions were obtained in the library. The result of Blastx indicated that 26 genes had homologous sequences and 7 genes showed high similarities with putative proteins; 2 genes did not get any homologous sequence or protein. Defense-related genes (40.3%) were most in the library; The energy metabolism and the cytoprotective genes were in the next place (23.4% and 14.9% respectively). The genes related to eucaryotic cell structure, protein synthesis, transduction and signal transduction were fewer (8.5%, 4.3%, 4.3% and 4.3% respectively). DMP can induce numerous genes expression in tobacco. Masses of genes are related to plant growth and stress resistance.