This study was aimed to investigate whether hydroquinone (HQ) can inhibit NF-kappaB expression activated by phorbol myristate acetate (PMA), and to explore the relationship between the mechanism and the hematology toxicity of benzene tentatively. The human bone marrow stromal cells (BMSC) were harvested by in vitro culture and their change of morphology were observed. The activity and protein expression of NF-kappaB p65 extracted from those BMSC were measured with immunohistochemistry and TransAM P65 kit. The results showed that in cells exposed to HQ, P65 transferred from cell nucleus to cytoplasma around cell nucleus and its concentration lowered by immunohistochemistry. And TransAM P65 kit assay revealed that HQ effects at different concentrations were distinctive at respective time. The detected parameters in 100 micromol/L HQ group were significantly different from control group after exposure for 72 hours. But the parameters at different time in micromol/L HQ group were not obviously different. It is concluded that hydroquinone can inhibit NF-kappaB activated by PMA in BMSCs culture. This kind of inhibitory action correlated with the concentration of HQ and exposure time.