Abstract: OBJECTIVE To study the processing mechanism of Stalactitum. METHODS The mechanism of Stalactitum was explored by comparative studying on determination, thermogravimetry, scanning electron microscope observation, FT-IR spectrum analysis, X-ray diffraction Fourier spectrum analysis, analysis of trace elements and chemical elements in blood of Stalactitum before and after processing. RESULTS After being processed, the assay of calcium in Stalactitum was increased obviously, its main chemical component CaCO₃ was decomposed into CaO partially, meanwhile, it was not the simple change of the components of Stalactitum, but significant changes of its phase and crystalloid. The number and proportion of the elements in Stalactitum were also changed, the content of Pb, Cd, As, Hg and Cu in Stalactitum were all accord with the limit regulations of China pharmacopoeia. Compared with raw Stalactitum, the concentrations of K and Na in blood in processing Stalactitum group were decreased, and Sn was detected in serum of rats. CONCLUSION The experimental studies show that after being processed, the texture of Stalactitum is loose which means grinding turned to easy, the effective components can be extracted easily. Processing has the function of decreasing toxicity and synergism. The results show that the processing on Stalactitum has certain significance.