The thermal decomposing curves of rutin in different heating speeds were obtained under dynamic conditions in nitrogen atmosphere,using non-isothermal thermogravimetric and derivative thermogravimetry methods（TG-DTG）.Four thermal analysis kinetic methods,e.g.Achar,Coats-Redfern,Kissinger and Ozawa method were used to speculate the probable mechanisms of thermal decomposing reaction and the kinetic parameters.The shelflives of rutin at sevral different temperatures were calculated by the kinetic parameters of first stage.With increase of the heating rate,the thermal decomposing tempreture of rutin rose.The most probable kinetic mechanisms of the three-stage thermal decomposition were nucleation and growth,three-dimensional diffusion,nucleation and growth,which correspond to Avrami-Erofeev Equation,Z.-L.-T.Equation and Avrami-Erofeev Equation,respectively.In accordance with the data of TG and Gaussian simulation,one molecule of rutin lost three oxygen atoms at the first stage of decomposition and lost ten oxygen atoms at the second stage while paraffins and one benzene ring were lost at the third stage.The shelflives of rutin at room temperature were about 15-2 years based on the apparent activation energy（Eα） and pre-exponential factor（A） of the first stage.