Characteristics, formation and migration of the particles carried by ascending gas flow in the concealed metal deposits were studied. In the research, the theory and method of geochemistry and of nano scale science and technology were adopted and more than ten metal deposits had been studied. The results showed that particles carried by ascending gas flow in surface sediments above concealed metal orebodies occur in forms of individual particles and particle aggregations. The shapes of individual particles are spherical, near-spherical, irregular, regular polygon, and long columnar. The particles are crystalline, amorphous, or partly ordered semi-crystalline. The shapes of aggregations are irregular, spherical, or near-spherical.