Abstract: The molecular structures of Fushun and Maoming kerogen were constructed based on the characterization techniques such as solid-state¹³C nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS) and ultimate analysis. Self-build kerogen models were modified on the basis of chemical bond concentration, chemical bonds concentration of experiment data and molecular structure match well, therefore constructed models have been proved to be accurate and reasonable from the perspective of chemical bonds. From the data of self-build and selected kerogen models, the relationship between metamorphic degree of oil shale kerogen with concentration of chemical bonds and energy density were studied. With the increase maturity of oil shale kerogen, the chemical bonds concentration between aromatic carbon and aromatic carbon, aliphatic carbon, hydrogen atom increase, the chemical bonds concentration between aliphatic carbon and aliphatic carbon, hydrogen atom decrease. Among them the chemical bonds concentration between the aromatic carbons, and that between aliphatic carbon and hydrogen atom change obviously. Valence electron energy and non-bond energy are two parts that make up total energy, being the steady chemical energy of oil shale kerogen and increase with increase of its metamorphic degree.