[en] Lead isotopic tracing is an effective method for uranium exploration,but it was not widely used due to the expensive instrument. The successful development of thermal ionization time-of-flight mass spectrometry (TI-TOF-MS) provided the possibility of using lead isotopes tracing economically in uranium exploration. Based on the laboratory-made economic TI-TOF-MS, the samples collected from the drill hole of uranium deposit in North China was analyzed for lead isotopic tracing experiment. The method of sample digestion,separation and enrichment of lead was introduced at first, and then the analysis & data processing procedure. TI-TOF-MS has an accuracy of 0.94%, 0.37 and 0.14% for the measurement the ratio of ²⁰⁴Pb/²⁰⁶Pb, ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb, which met the requirement of lead isotopic tracing. The application results suggest that the composition of lead isotopes by TI-TOF-MS can be used as the sign for uranium exploration. (authors)