Radon-detection is an effective geophysical radiometry. In this paper, for the aim of groundwater-rich zones, radon-detection was applied in exploration of fracture groundwater resource in Qingyuan Mountains in Quanzhou, east-southern China. And the results shown that there were two obvious faults named F1 and F2, with the direction of North-West-West and North-West in Qingyuan Mountains. Combining with the geological data, F1 fault was engendered from orogeny, and F2 fault was original from invading of granitoids and tectonic activity, they were an ideal reserving space of groundwater.