Epigenetic regulation of chromatin structure is fundamental to the activation or repression of genes in many biological processes. There has been an explosion of research relating to various modes of epigenetic regulation, such as DNA methylation, post-translational histone tail modifications, noncoding RNA control of chromatin structure, and nucleosome remodeling. We comprehensively explore how epigenetic landscapes impact on genome expression, organization and inheritance, and recent interest and research focus surround the direct connections between biological events and chromatin dynamics. This talk will contain two independent parts: epigenetic control of circadian clock and cellular pluripotency. Evidence of rhythmic changes in chromatin structure has opened new and exciting ways for regulation of circadian gene expression. This scheme ensures an appropriate synchronization of circadian oscillation with the environment. In addition, technological advances in genome-wide epigenetic profiling have been primary drivers for elucidating the epigenetic control of cellular identity in biological organisms. This talk will also illustrate the molecular mechanism underlying cellular reprogramming and its possible application to plant regeneration.