Abstract: The onerous chemical extractions for soil organic matter (SOM) fractions do not always produce satisfactory ¹⁴C dates. In an effort to develop an alternative method, the pyrolysis-combustion technique was investigated to partition SOM into pyrolysis volative (Py-V) and pyrolysis residue (Py-R) at 400℃, and dated the two component parts separately by Accelerate Mass Spectrometry (AMS). Compared with the environmental archaeology sequence at the Licun Holocene profile, the Py-V fractions yielded ¹⁴C data more reasonable than the counterpart Py-R fractions in the culture sequence, but on the contrary, the Py-R fractions yield ¹⁴C data more convinced in the loess stratigraphic sequence. Zhouyuan loess was probably developed about 9 300 BP ago, and accumulated for 6 000 years.