A systematic stuuy and test of feasibility of uranium exploration by the fissiontrack method has been carried out.It is shown that the method has high sensitivity andreproducibility for uranium determination in natural water. The test indicated that thesensitivity and accuracy of the method in mapping uranium-rich halos in test grounds were higher than laser-fluorometry which was regarded as the most sensitive method before. A large area （560km2） exploration of uranium has been carried out and a uranium ore of industrial grade found. Some new rule of uranium-ore formation has been drawn from the study.