The uranium concentrations in natural water collected in the fields of uranium ore exploration with fission track method have been determined. It shows that the results of fission track method are consistent with that of fluoro-colorimetry and laser fiuorometry for the same samples of water with uranium concentration in the region from 10

-4

to 10

-8

g/l. For water samples with lower uranium concentration (≤10

-8

g/l)

the fission track method can still give accurate or referential results. but the other two methods failed. The reproducibility of fission track method has been checked and discussed using samples collected in the same fields of uranium ore exploration. The effects of the concentration of the impurities in natural water on the determination of uranium concentration are analysed and discussed as well.