A narrow-pulse Q-switched tunable Cr:LiSAF laser is reported in this paper. Stable Q-switched output was obtained at 850 nm with energy of 214 mJ per pulse and pulse-width of 20 ns (FWHM) and linewidth less then 0.2 nm. The factors inducing damage of the Cr:LiSAF crystal were discussed, and a dual-wavelength tunable laser based on Cr:LiSAF is studied which can be used in DIAL (differential absorption lidar ) system.