Adopting the two grating cavities and lengthening the gain region of discharge, the output character of the TEA CO2 11μm lineswere studied. Under the optimum proportion ofmixing gases 18. 4% CO2 , 23. 7% N2 , 57. 9% He and at total pressure of 430 ×133. 3Pa, several laser lineswere observed. The output character of the laser line is studied which wavelength is 11013nm. The pulse width of wavelength 11013nm is 400ns around and the pulse width varies with the main discharge voltage variation. L ine’s energy varieswith the disp lacement of grating. While the centre of grating is in the axis of discharge chamber, the maximal energy output will appear. The energy distribution of the spot is close to the energy distribution of the lower-ordermode or fundamentalmode.