Using Point-by-Point method,long period fiber gratings were inscribed in the high temperature resistant fiber by an infrared femtosecond laser.Characteristics of the high temperature resistant fiber was analyzed theoretically.The experiment with long period fiber gratings contained high temperature resistant coating layer indicates that the shift of resonant peak at the temperature range from 20 ℃~300 ℃ keeps a good linearity and the temperature sensitivity is 0.060 5 nm/℃.The coating of the long period fiber gratings is not carbonized due to the existence of the high temperature resistant polyimide materials and grating sensor with good performance.The result shows that the high temperature resistant long period fiber gratings can be used in the high temperature environment for long term application.