Abstract: In order to find out the water bursting channels and hydrodynamic relation of different aquifers in limestone aquifer under floor of A group coal mining, NH₄Cl and KI were adopted as the tracer and put into Ordovician limestone aquifers, and coccinellin was used as the tracer and put into Cambrian limestone aquifers by observation well. Meanwhile water samples were collected at intervals of the water inrush point. According to the curve relationship between the concentration and time, absorbance and time, the results of test and analysis indicate that there are 4 channels in the Ordovician limestone aquifers, and 3 channels in the Cambrian limestone aquifers. There is a hydrodynamic relation in different limestone aquifers, and source of water comes from different limestone aquifers.