The nonlinear optical crystal grown from the melt GaSe∶ AgGaSe2(10%,mass percent) is identified as acentrosymmetric e-GaSe∶ Ag(≤0.04%,mass percent) and is used for phase matched frequency conversion.The silver presence results in 30% increase in microhardness,which allows the crystal to be cut and polished at arbitrary direction.The optical properties from visible to mid-IR and further THz ranges are studied in detail.It demonstrates that the absorption coefficient of GaSe∶ Ag(≤0.04%,mass percent) crystal is twice that of a pure GeSe,and the CO2 laser Second Harmonic Generation(SHG) efficiency is about 1.7 times that of ZnGeP2 crystal.