The senescent phenotype of human embryo lung diploid fibroblasts was obtained by four treatments of early passage cells with 50 μmol/L H₂O₂ for 30 min every 2 days. After total mRNA extraction from the two kinds of cells, the young cells and H₂O₂-induced premature senesence cells，the cDNA of two kinds of cells were labled by Cy3 and Cy5 respectively were hybridized with microarray containing 4 096 human genes. The gene expression changes were identified by GnePix 4000B and GenePix 3.0. 123 genes changed their expression significantly, which involved in progress of cell cycle,metabolism and protein processing, formation and modification of cytoskeleton and extracellular matrix and signal transduction, and the most interesting finding was that secretory function seemed to be enhanced in premature senescence of fibroblasts.