Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method,in which two-step-thermal-evaporation is used to control CdSe sources’ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width,50 nm in thickness,and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photoluminescence indicates that the lasing emission at 710 nm has been observed under optical pumping(266 nm) at power densities of 25-153 kW/cm2. The full width half maximum(FWHM) of the lasing mode is 0.67 nm Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, which two-step-thermal-evaporation is used to control CdSe sources’ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photoluminescence that the lasing emission at 710 nm has been observed under optical pumping 266 nm) at power densities of 25-153 kW / cm2. The full width half maximum (FWHM) of the lasing mode is 0.67 nm