Abstract: The temperature sensing character of fiber Bragg grating（FBG）is influenced by its structure and composition.In the existing temperature compensation methods adopting referenced FBG,the influences of referenced FBG structure were almost not taken into account.By means of mechanical analyses and mathematical emulations,the actual temperature responses of coated FBG and jacketed FBG were studied.The temperature sensing character formulas considering the actual fiber structure were deduced, and the method of quantitative error analysis in reference FBG temperature compensation was also given for the first time.The research is helpful in evaluating the strain state of structure accurately based on measuring results,and also provides theoretical bases for selecting reasonable parameters of FBG coating in practical applications.