The level of acetylation of histones in nucleosomes is related to the longevity of yeast and animals. However, the mechanisms by which acetylation and deacetylation affect longevity remain unclear. In present study, we investigated the influence of histone acetylation modification on the expression of hsp22 gene and the lifespan in Drosophila melanogaster using histone deacetylase (HDAC) inhibitor Trichostatin A (TSA). The results showed that TSA could extend the lifespan of Drosophila melanogaster. Furthermore, TSA significantly promoted the hsp22 gene transcription, and affected the chromatin morphology at the locus of hsp22 gene along the polytene chromosome. Present data implicate that TSA may affect the lifespan of Drosophila through changing the level of histone acetylation and influencing the expression of hsp22 gene that is related to aging.