In this paper, based on the transfer matrix method, the transmission properties in the infrared (IR) region for one-dimensional binary and ternary photonic crystals under the effect of temperature variations have been theoretically studied. Both thermal expansion effect and thermo-optical effect are considered simultaneously. The numerical results show that the photonic band gap can be significantly enlarged compared to the photonic band gap at room temperature. Furthermore, the calculated transmission characteristics in the wavelength domain demonstrate that, ternary structure has a significant effect in the width of the photonic band gap compared to the usual binary photonic
crystals. The roles played by the related parameters, such as the thickness of the constituent materials will be discussed and illustrated.