Employing a fiber- coupled diode- laser with a center wavelength of 852.3 nm and a linewidth of 0.17 nm as the pump source, and using a 5 mm long cesium vapor cell with 60 kPa helium and 20 kPa ethane as laser medium, an experimental investigation of LD- end- pumped cesium vapor laser is carried out. Under an operating temperature of 107.6 ℃ , the laser output performance is optimized by changing the reflectivity of output coupler. Using an optimized reflectivity of 48.79% , 1.16 W 894.57 nm laser is obtained at an incident continuous- wave pump power of 4.76 W, corresponding an optical- optical efficiency of 24.4% and a slopeefficiency of 28.8% , respectively.Steady cesium laser with an output power of 2.5 W is obtained under 14.1 W pulsed pump power.