A diode end pumped single frequency Tm:GdVO 4 laser at room temperature was reported. The maximal output power of single frequency is as high as 66 mW by using two uncoated fused etalons, which are respectively 0.05 mm thick YAG and 1 mm thick quartz. We obtained the single frequency Tm:GdVO 4 laser at 1875.1 nm. The slope efficiency is 1.5%. The change of the lasing wavelength on temperature was also measured. The single longitudinal mode (SLM) laser can be used as a seed laser for coherent wind measure ments and differential absorption LIDAR systems.