The Dongjun deposit, located in the Hailaer Jurassic volcanic faultdepress basin, is a typical hydrothermal lead—zinc—silver deposit generated from volcanic rocks, which is characterized by significant hydrothermal alternation, apparent orecontrolling fault of metallogenic, many orebodies with small scale, etc. Volcanic rocks have high content of Alkali (K2O+Na2O=5.93％～8.26％), with the average value of Na2O/K2O at 1.81, relatively rich in light rare earths（LaN/YbN=1672～23.31）,and with slightly Eu negative abnormality. Also, Largeion lithophile elements (LILE) are richer than high field strength elements（HFSE）, while Nb、Ta、Ti are relative drawdown, compared to LREE and LILE. The δ34S values of sulfide ores vary from +4.48‰ and +6.97‰ and are typical of mantle S. In sulfide ores,the n(206Pb)/n(204Pb), n(207Pb)/ n(204Pb) and n(208Pb)/ n(204Pb) ratios vary in the ranges of 183143～18.4315,15.4934～15.6265 and 37.9810～38.4236 respectively, showing that the UPb is richer, while ThPb is slightly less. Besides, in volcanic rocks, [n(87 Sr)/n(86Sr)]i=070506～070512，[n(143Nd)/n(147Nd)]i=0.512521～0.512602，εNd(t) values of 1.4～2.9. The geological and geochemical features of ore deposit indicate that the oreforming matter is from magma system or the host rock, while the magma is mainly from the mantle rich in light rare earths, maybe mixed with a small amount of crustal materials.