Histone deacetylases (HDACs) mediate histone deacetylation and act in concert with histone acetyltransferases to regulate dynamic and reversible histone acetylation which modifies chromatin structure and function, affects gene transcription, thus, controlling multiple cellular processes. HDACs are widely distributed in almost all eukaryotes, and there have been many researches focusing on plant HDACs recently. An increasing number of HDAC genes have been identified and characterized in a variety of plant species and the functions of certain HDACs have been studied. The present studies indicate that HDACs play a key role in regulating plant growth, development and stress responses. This paper reviews recent findings on HDACs and their functions in plants, especially their roles in development and stress responses.