Nucleosomes, which are the fundamental building blocks of chromatin, are highly dynamic, they play vital roles in the formation of higher‐order chromatin structures and orchestrate gene regulation. Nucleosome structures, histone modifications, nucleosome‐binding proteins, and their functions are being gradually unravelled with the development of epigenetics. With the continuous development of research approaches such as cryo‐EM, FRET and next‐generation sequencing for genome‐wide analysis of nucleosomes, the understanding of nucleosomes is getting wider and deeper. Herein, we review recent progress in research on nucleosomes and epigenetics, from nucleosome structure to chromatin formation, with a focus on chemical aspects. Basic knowledge of the nucleosome (nucleosome structure, nucleosome position sequence, nucleosome assembly and remodeling), epigenetic modifications, chromatin structure, chemical biology methods and nucleosome, observation nucleosome by AFM, phase separation and nucleosomes are described in this review.