Objective To explore the action of formaldehyde inducing DNA protein crosslinks(DPC) and to test the detection method. Methods This study took human blood lymphocyte as experimental material, chose 0、0 005、0 025、0 125、0 625 mmol/L five formaldehyde concentrations, and used KCl SDS method to detect DPC. Results At low concentrations(0 005, 0 025 mmol/L) formaldehyde cold not induce DPC(P>0 05); but at high concentrations(0 125, 0 625 mmol/L), it could induce DPC significantly(P