Abstract: Determination of α particle nuclear track density by a thermal analysis method was applied to geological dating. The contents of ²³⁸U、²³²Th and ¹⁴⁷Sm isotopes in apatite samples from Ma'anshan Anhui were measured by the neutron activation analysis method. Besides, taking the Durango apatite as reference, the content of α particle nuclear track was measured by the thermal analysis method. At last the geological age of the apatite samples was calculated as 3.63×10⁷ a. By comparison with the other geological data, It is reasonable that the geological age was 30 million years or so.