Abstract: The enhanced temperature sensitivities of Fiber Bragg Gratings (FBGs) slice-packaged with copper, aluminum, perspex and PTFE were studied experimentally. The results show that when the coated fiber tails on both sides of FBG are bonded on substrate materials, the temperature sensitivity coefficients are about 2.3 times, 2.9 times, 5.2 times, and 11.7 times that of a bare FBG, respectively. However, the measurement reproducibility of the results is unsatisfactory due to the fact that the thermal expansion of substrate materials at higher temperature will inevitably lead to a separation of fiber cladding from coating layer. For experimental optimization, the experiments under the uncoated tail of FBG are carried out based on the aforementioned four substrate materials. The reflection wavelengths have a good linear relationship with the temperature change within the measurement temperature range. The temperature sensitivity coefficients of FBGs are enhanced to 3 times, 3.4 times, 9.2 times, 12.6 times, respectively,and the results show a good measurement reproducibility. The research results provide necessary and useful data support and reference for the future research on the temperature sensitivity enhancement of slice-packaged fiber Bragg grating sensors.