Abstract: The particle size, morphology and crystal type of talc have important effects on its effective application and the function of the end products. Current study of talc focuses mainly on the surface modification, but there are few studies on their morphology and crystalline structure. The changes of morphology and crystalline structure of talc from Liaoning induced by strong mechanic grinding were investigated using X-ray Fluorescence Spectrometry (XRF), X-ray Diffraction (XRD), Infrared Spectroscopy, Particle Size Analyzer and Field Emission Scanning Microscopy (FE-SEM). The results show that the MgO/SiO₂ molar ratio is 0.45, which is lower than the calculated value (0.75) for ideal talc. The crystalline structure has been destroyed after prolonged grinding. Namely, the structure of talc is changed from a crystalline state into an amorphous state after grinding. With the increase of grinding time, the particle size repeats diminution, enlargement, diminution processes. The morphology of powder was changed after grinding, which gradually changed to be a torispherical shape, and then had a refinement-reunion-refinement process. The conclusion of the circulation change has an important guiding significance and reference value for the further processing and application of talc and the study of related mineral powders.