Abstract:By using quartz thermometer and the experiential formula qSiO2=(TSiO2-b)/m given by C.A. Swanberg and P. Morgan in 1980s,this paper studies the silica heat flow values alongNorth-South seismic belt,and analyses their trend and fractal property. In contrast to geologi-cal background,the paper also discusses the relationship between silica heat flow values and tectonic activities and prospects of application of silica-heat-flow method.