Abstract: Objective To observe the differentially expressed genes in human embryonic lung fibroblasts (HELF) induced by small-dose hydroquinone (HQ) using fluorescence differential display-PCR (DD-PCR). Methods According to the dose-effect relation of HQ toxicity we established previously, HQ dose that did not induce observed cell damage or proliferation arrest was defined as low dose (100 pmol/L), and that causing obvious cell damage as the high dose (100 μmmol/L). The cells were then treated with low or high dose of HQ, or exposed to high-dose HQ following pretreatment with low-dose HQ for some time, respectively. Fluorescence DD-PCR was performed and 33 differentially expressed genes were identified in the cells with different treatments, and 8 of the identified genes were amplified, cloned, sequenced and blasted. Results Seven of the 8 amplified genes were unknown genes, and the left one was identified as a known gene highly homologous to that encoding Homo sapiens Rap1 interacting factor 1 (RIF1). Conclusion Low-dose HQ can induce damage tolerance in HELF, and identification of the differentially expressed genes may provide valuable sight into the mechanism of HQ-induced damage tolerance.