Liquid-crystal spatial light modulator (LC-SLM) has the attractive advantages of large number of correcting elements, low applied voltage, easy control and low cost etc. as an emerging wave-front corrector. Based on the investigation of its time-space characteristics, the capability and limitations of LC-SLM in adaptive astronomical imaging application systems were discussed. An adaptive optical system with a LC-SLM and a Shack-Hartmann sensor was close-looped. As a result, a static aberration, which is mainly composed of low order aberrations, was corrected. RMS value and PV value after closed-loop correction are reduced from 0.628λ, 2.872λ to 0.031λ and 0.337λ, with a Strehl ratio improvement from 0.04 to near diffraction-limited of 0.81. Apart from that, the diffraction efficiency of LC-SLM was calculated and measured. From the result, LC-SLM is capable of correcting atmosphere turbulence nicely. However, Low optical efficiency and response speed are huge drawbacks to limit LC-SLM in a practical adaptive optical system to correct atmospheric aberration in real time and using for faint object.