The thermal instability is a big problem in arrayed-waveguide gratings (AWG). A general method to study the central wavelength temperature sensitivity is developed with theoretically considering thermo-optic effect, stress-optic effect, thermal expansion and stress-strain relation. By combination of elastic multilayer theory and stress concentration effect, analytical stress solutions in the core layer are obtained. Based on the results of asymmetrical anisotropy planar waveguides, the effective index and its temperature coefficient in buried channel waveguides are calculated by using the effective index method. And then, the solutions are used to estimate temperature sensitivity of AWG central wavelength. The temperature sensitivity controlled by the thermal stresses induced by attaching an aluminum plate is also discussed. The results show that the temperature sensitivity could be optimized after attaching an aluminum plate on the bottom of arrayed waveguides. For the TE mode, the temperature coefficient of central wavelength is reduced to 5.9 pm/℃, and for the TM mode, that is reduced to 8.0 pm/℃.