Objective：To explore the relationship and stability between age and telomere length of oral epithelial cells of saliva spot，and to discuss whether freshness of sample or sample collected by two methods affects the length change，in order to provide forensic science with evidence to deduce age by means of micro-sample. Methods：Forty fresh saliva samples were collected from healthy in－dividuals，which was divided into five groups，aged from 0 to 100 years old. Those saliva samples were made into fresh oral swabs and saliva spots at different periods（1，7，14，28 d）. DNA was extracted by paramagnetic particle method and the terminal restriction frag－ment length was measured by quantitative polymerase chain reaction with the analysis of linear regression. Results：The average TRF length showed a shortening tendency with aging，while samples collected by two methods and freshness of sample did not affect this parameter. The regression equation for age estimation was Y=-75.006X+101.193. Conclusion：The terminal restriction fragment length and age of donors show an inverse correction and there is no difference in samples collected by two methods and freshness of sample possible to infer individuals age by terminal restriction fragment length assay.
