The formula process of bluish white porcelain body is still in the speculation stage. There exist no tangible proofs and simulated experiments to clarify the underlying craft. In order to explore the formula process, various china clays near the Fanchang Kiln have been characterized, and simulative firing experiments in the virtue of ancient porcelain technology have also been performed. Different characterizations including wavelength-dispersive X-ray fluorescence (WDXRF) XRD and FT-IR spectra was applied to determine the composition of the several china clays nearby the Fanchang Kiln. Meanwhile, the firing temperature was explored by TG-DSC analysis. Based on the above analysis, simulation firing was performed to study the possible firing process. And the microstructures of resultant samples were characterized by optical microscopy. Experiments evidences indicated that these china clays can be used as the raw material to fire bluish white porcelain body of the Fanchang Kiln. Considering aluminum content of these china clays is lower than that of the bluish white porcelain body, some materials containing high alumina component may be introduced in the production of the bluish white porcelain. This research has huge academic significance in understanding the production technology and promoting the status of the Fanchang Kiln in the development history of Chinese ceramic technology. This research also is helpful to improve the modern ceramic technology.