The theoretical results of the oscillated threshold for dual-wavelength, continue-wave Yb∶YAG laser were presented, and then its output was experimentally investigated. In our experiment setup, a plane-concave cavity was employed for laser oscillating by end-pumping with a 940nm fiber coupling laser diode. A Yb∶YAG crystal was taken as the laser crystal in the cavity. The single wavelength and dual-wavelength laser were respectively obtained by using the Output Coupling (OC) of 10%, 15%, and 20%. At the highest pump power of 20W, the maximum output power at 1 050 nm is 3.94 W at the OC of 10% and the maximum output power at 1 030 nm is 3.40 W at the OC of 20%. The corresponding optical to optical conversion efficiencies are 19.7% and 17.0%, respectively. At the output coupling of 15%, the dual-wavelength output power of 0.79 W was obtained at the pump power of 11.7 W, corresponding to an optical-to-optical conversion efficiency of 6.8%. It is experimentally found that the output power ratio P1 030 nm/P1 050 nm was about 1∶1.3. The central wavelengths of the dual-wavelength laser were located at 1 030.31 nm and 1 047.50 nm by using a grating spectrometer. At an output power at 1 030 nm of 3.0 W, its output power stability of RMS is determined to be better than 0.18% in a 30 min operation. The proposed model gives results that agree fairly well with the experimental data. Our results suggest that high efficient, compact stable Yb-doping dual-wavelength lasers can be designed from our model.