It is found that the torsion characteristics of the long-period fiber grating (LPFG) are novel,which is written symmetrically by three-beam focused high-frequency CO2 laser pulses. Firstly,when the length of the twisted fiber is close to the length of the LPFG,the torsion characteristics have obvious relevance with the twisting direction. If the LPFG is twisted clockwise,the resonant wavelength and the peak loss will decrease linearly with the twist rate increasing. If the LPFG is twisted anticlockwise,the resonant wavelength and the peak loss will increase linearly with the twist rate increasing. The average sensitivities of resonant wavelength and peak loss are 0.133 nm/(rad·m-1) and 0.061 dBm/(rad·m-1) respectively. Secondly,when the twisted fiber is much longer than the LPFG,the torsion characteristics oscillate periodically;and the number of the oscillation (10 periods) overcomes the number of turns (6 turns) that the fiber has been twisted. The overall characteristics are basically unchanged if the volatilities are ignored. The torsion characteristics are analyzed theoretically by taking into the consideration of the twist-induced elliptic birefringence. Moreover it is found that the linear birefringence in the LPFG also plays a decisive role in the torsion characteristics.