By measuring the emission spectra and the fluorescence lifetime of the 4I13=2 state of Er3+ ions in Gd2SiO5 crystal at different temperatures, the effects of temperature on the spectra and the lifetime of the 4I13=2 state are investigated. When the temperature increases, the emission line width for the 4I13=2 -> 4I15=2 transition is broadened, and the main emission lines at 1 596, 1 609, and 1 644 nm shifte toward shorter wavelengths. The measured lifetime of the 4I13=2 state decreases from 13.2 to 8.4 ms with temperature increase from 13 to 300 K, which is mainly due to the temperature dependence of multiphonon relaxation between the 4I13=2 and 4I15=2 states and the changing population distribution among the Stark levels within the 4I13=2 state. The experimental results imply that low temperature condition is better for the ~1.6- \mu m laser output.