The light power-current (L-I) characteristics of vertical cavity surface emitting lasers (VCSEL)，which have the same fabrication process and structure, but different detunings of Fabry-Perot (FP) resonance from the gain peaks at room temperature, were measured in the temperature range from 261K to 369K. The relationships between the output light power, threshold current, slope efficiency and lasing wavelength and the temperature were studied using the obtained characteristics in combination with the test results of their reflectivity spectra and photoluminescence signals, as well as the simulated results of their reflectivity spectra and gain spectra at different temperatures. The temperature characteristics of the new material AlInGaAs were found. The effect which the differences between the gain spectrum and the FP resonance had on the output characteristics, especially on the threshold current had been obtained. We found that VCSEL devices with minimal threshold currents and small threshold current change with temperature at room temperature could be obtained by adjusting the detuning of Fabry-Perot (FP) resonance from the gain peak. Using this method, AlInGaAs/AlGaAs strained quantum well VCSEL devices which have the characteristic temperature of 333K, and minimal threshold current and small threshold current change with temperature in the 321K to 345K range were fabricated.