Archaeomagnetic techniques provide important qualitative and quantitative analysis methods for heating history of archaeological sites. The Xiaonanshan site, located at northeastern Heilongjiang Province, is one of the most important prehistoric sites in northeast China. The earliest discovered human activity relics on this site trace back to the Late Pleistocene. The site unearthed series of remains and relics of human activity since 16 ka, including many stone artifacts, some potteries, and a few remains of suspected fire use related to human lifestyles. In this study, we collected soil samples from the suspected fire areas and surround area, and conducted a series of rock magnetic experiments, including low-frequency magnetic susceptibility (χLF), step-wise variation of susceptibility versus temperature (χ-T), hysteresis loop, isothermal remanent magnetization (IRM) acquisition curves, back field demagnetization curves (BFD) and first order reversal curve (FORC) diagrams, to provide quantitative data for the heating history, e.g., heating temperature and heating range, of the site. The results indicate that the two suspected fire areas (ZB, ZC) show higher χLF, higher saturation IRM, stronger signal of FORC, and better thermal stability between 400~600℃, while the suspected fire area ZA, with surface soil removed during excavation, and surrounding area show lower χLF, lower saturation IRM, weaker signal of FORC, and gradually thermal alteration during the heating process indicated by χ-T curves. The rock magnetic results support the two suspected fire areas ZB and ZC were burnt, while ZA and surrounding areas were probably not heated, at least not to high temperatures as ZB and ZC. The thermal stability between 400~600℃ and obviously thermal transformation at 700℃ of the χ-T curves indicate that the historical heating temperatures of firing areas are about 600~700℃.