Tunable high repetition rate transversely excited atmospheric-pressure (TEA) CO2 laser has potential applications in laser chemistry, laser radar and optically pumped far-infrared laser investigation. In this paper, with the aim of development of kilowatt-level high repetition rate tunable TEA CO2 laser, inject-locking method, low fitness Fabry-Perot (F-P) coupler method and grating line selection method were investigated. With the method of grating line selection, kilowatt-level high repetition rate tunable TEA CO2 laser output was realized by grating resonator. The pulse energies of 10P(20), 10R(20), 9P(20) and 9R(20) are 5.8 J, 5.8 J, 5.5 J and 5.6 J respectively, at the repetition rate of 200 Hz. The far-field divergence angles are 1.66 mrad (horizontal) and 1.43 mrad (vertical), namely, about 2 times of diffraction limitation.