The studies of chromatin 3D structure help us to understand its formation and function. Techniques combining chromosome conformation capture and next generation sequencing can capture chromatin structure information and has been applied to several different species and cell lines. We built 3DGD (3D Genome Database), a database that currently collected Hi-C data on four species, for easy accessing and visualization of chromatin 3D structure data. With the integration of other omics data such as genome-wide protein-DNA-binding data, this data source would be useful for researchers interested in chromatin structure and its biological functions.