Abstract: The paper analyzed and studied the character of 3.3 kV underground mine power system through steady-state leakage-current,transient leakage-current,body safety and arc grounding over-vol-(tage.) These transient fault parameters of grounding fault are emulated in the computer.Some technical(parameters) were presented.These providid theoretic dates for researching the method of neutral point in(3.3 kV) underground mine power system