2,3-Dihydro-9,10-dihydroxy-1,4-anthraquinone（R）was synthesized and characterized by 1H NMR，IR，MS and UV-Vis spectrometry.Based on the facts that R can emit intense and stable solid substrate-room temperature phosphorescence(SS-RTP) on solid substrate，and α，α dipyridine can activate Hg2+ to catalyze the reaction of H2O2 oxidizing R to form non phosphorescence compound, a new solid substrat-room temperature phosphorescence quenching method was established for the determination of trace mercury.Under the optimum condition，the relationship between the ΔIp of the emitting intensity and 1.60-160 fg/spot Hg2+（corresponding concentration:0.004 0-0.40 μg/L，sample volume:0.4 μL/spot） conformed to Beer law.The regression equation was ΔIp=11.56＋0.549 2 m（fg/spot） （r=0.999 1）.The limit detection was 0.26 fg/spot（corresponding Hg2+ concentration:6.5× 10-10 g/L）.The spiked recoveries were in the range of 97%-103% with RSDs of 2.3%-4.1%.The RSDs（n=11） of 0.004 0 μg/L and 0.40 μg/L Hg2+ were 2.6% and 4.1%，respectively.The method showed good repeatability，sensitivity and high precision.It was applied in the determination of trace mercury （Ⅱ） in real samples with satisfactory results.