This paper reports the experimental results on the thermogravimetric characteristic of straw combustion and influence of different experimental conditions upon the thermogravimetric characteristic of straw. The ignition and combustion characteristicss of straw are studied. According to the experimental results.it is suggested that the initial release temperature of corn straw and wheat straw volatilization reduces and the initial release temperature of rice straw volatilization rise with the increase of the temperature-increasing rate. The burning out rate of corn straw,wheat straw and rice straw increase with the increase of the temperature-increasing rate.