Firing temperature is a key technical parameter for the study of the development of ancient ceramic technology. Different firing temperatures might be used for ceramics from the varied chronological periods and functions. Thermal expansion analysis, can only be used to study high-fired ceramics and porcelains. It is challenging to determine the firing temperature of low-fired potteries from Neolithic and Bronze Age China. Current research developed an innovative method for studying ceramic firing temperature based on FTIR analysis. The structure of clay minerals in ceramics would be altered when exposed to high temperature, and a series of changes would happen to their FTIR bands at 3 625， 1 030， 640， 560 and 525 cm-1. These altered bands are potential indicators of ceramic firing temperature. Seven experimental ceramic samples fired between 450 ℃ and 1 050 ℃ were analyzed with FTIR, and the result shows a strong correlation between firing temperature and spectral features. In this light, the original firing temperature of ancient ceramics could be inferred based on their IR spectrum within an interval of 100℃. This method analysed two Shang period pottery samples and two casting mould samples. It is revealed that one pottery sample was fired between 550 ℃ and 650 ℃ while the other one was higher than 850 ℃. This result indicates highly varied firing techniques for different types of potteries. Both casting mould samples were fired below 550 ℃, demonstrating that the ceramics with different functions were consciously fired at different temperatures. Since FTIR is a fast analytical technique and requires only a small sample, it can be used to determine firing temperatures for large assemblages of archaeological ceramics without significant damage to the integrity of artefacts. It has great potential in investigating the development of ceramic firing techniques and revealing their technological and cultural significance.