Objective In order to explore the damage mechanism of chromosome telomere in mice indnced by formaldehyde. Methods Kunming mice were exposed to formaldehyde at different doses (10, 20, 40 mg/kg)through gavage for seven consecutive days, then chromosome telomere DNA repeat sequence relative length (OD260)of all mice's blood, liver and kidney cells were detected by PCR method in different groups. Results The length of chromosome telomere DNA repeat sequence of blood, liver and kidney cells shortened in 10, 20 and 40 mg/kg formaldehyde groups...