The new scheme of using a long period grating for simultaneousdiscriminating measurement of temperature and strain is proposed. The scheme isbased on the long period grating’s spectrum characteristics. The spectrum iscomposed of multiple and different loss peak. The resonant wavelength of thefirst and fourth-order loss peak with different temperature and strainsensitivity was selected in this experiment. The wavelength shift resulting fromparameter variation can be obtained by observing its corresponding spectrum. Thetemperature was acquired by a study on the temperature characteristic of a LPG.The strain sensitivity was obtained by the research on the strain characteristicof a LPG. The standard matrix equation was set up and solved according to thecorresponding parameter. The authors know by calculating the standard matrixequation that the cross-sensitivity has little influence on the measurement ofthe parameter. As the effect of cross-sensitivity is lower than the resolution ofthe LPG in this case, we can eliminate the deviation due to the cross-sensitiveby appropriate compensation. The errors of temperature and strain were calculatedto be ±0.92 ℃ and ±22 με respectively. The cross-sensitivity betweentemperature and strain was decreased and the measuring precision of the systemwas improved by using this scheme in which a single long period grating was usedto test two measurands. By comparison between the applied and the calculatedtemperature and strain of a LPG, the experiment results showed that the methodsare feasible.The experimental system is small and the cost is relatively low. Theexperimental device is simple and practical and has good application prospect.Simultaneous measurement; FiberBK2009370), 航空科学基金项目(2008ZD52047)和南京航空航天大学研究生创新基地(实验室)开放基金项目(200901001)资助