Gold deposit forming and metallogenetic prognostication have been worked for a long time at both home and abroad. Our study demonstrated that formation of gold deposits in greenstone belt and gold-bearing dark rock series, and hematite containing big gold grain gold might be controlled by mineral magnetism. The main point views were as follows. 1)To analyze the gold-bearing mechanism in greenstone belt and the gold-bearing conditions in different magnetic rocks, the relations between gold grain size and magnetic force strength were revealed. 2)Near the electric minerals(gold, pyrite and pyrrhotite), electric current could produce a magnetic and a magnetic flux fields(H field and B field), the both fields having a relation with metallogenetic medium, based on the both formation process of ore-bearing liquid and condition of gold enrichment being traced. 3)The markers, such as mineral magnetic halo and mineral magnetic vector, for discovering ore deposits were set up based on the mineral magnetic characters. 4)The mineral magnetism should be regarded as one of main conditions in gold deposits forming and metallogenetic prognostication in addition to temperature and pressure.