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The article studies the pyrolytic properties of the binderless hot-briquetted lignite in East Mongolia during the process of middle-temperature and low-temperature pyrolysis,mainly on the law of semi-coke characteristics and the tar extracts,pyrolysis water,gas velocity,gas contents at different temperature,meanwhile compared the pyrolysis characteristics of the raw coal and briquette.The research shows that as the temperature increasing,the semi-coke yield obtained by pyrolysis of lignite briquette is nearly 6% higher than raw coal,volatile contents of semi-coke decreased by 2%,fixed carbon (FCdaf) of lignite briquette 1.5-4% higher than raw coal.The semi-coke SEM of briquette changed from honeycomb-like structure to softening surface and collapsed cracks with the pyrolysis temperature rising from 400℃ to 800.Tar releasing is approximately equal to raw coal,the pyrolysis water yield of raw coal is about13.85% higher than the briquette,the gas yield of briquette is about 7% higher than raw coal,gas velocity of briquette is higher than raw coal,calorific value of briquette gas is about 3 MJ/Nm3 higher than raw coal,while gas composition rules are approximately equal,and both with a high content of CO and H2,and as well as suitable for synthesis gas.Meanwhile The FTIR spectra of briquette tar were also quite similar to raw coal,the tar of briquette and raw coal are both contain abundant-OH functional groups,as well as various forms of existence-CH2 and-CH3,which contains many aliphatic material.In addition,the pores of lignite occurred shrinkage and collapse in the process of drying and bindedess briquetting,and there was little change in the categories of surface functional groups,but the contents of oxygen functional groups are reduced in different degrees,The main process of binderless briquetting is to remove moisture from coal samples.It relatively make gas releasing process and water-oil separation more easily and make the gas calorific value improved.