Abstract: As no experimental method can be adopted to directly measure crude oil maturity, biomarker parameters are usually used as proxies. Common biomarker parameters are mostly applied to make a qualitative analyses, but they may not be applicable to measure high maturity crude oil. High temperature thermal simulation experiments were conducted on low maturity source rock samples to analyze features of liquid aromatic products at different stages of thermal evolution. The relationship between various aromatic parameters and thermal maturity was explored. Experimental results showed that methylphenanthrene and trimethyl naphthalene have significant correlations with thermal maturity. On this basis, some equations for extrapolating various parameters to thermal maturity were established. Thermal maturity of oil sand samples from the Hala'alate area was determined and showed that the Permian, Triassic, and Jurassic crude oil has a lower maturity, while the Cretaceous crude oil has a high maturity.