卷云的消光后向散射比是研究卷云光学特性的一个重要参量，我们的工作就是利用米散射激光雷达探测的大气和卷云的后向散射信号来获得间断出现的高层薄卷云的消光后向散射比。在无大的天气系统过境的情况下，通过对定点观测到的雷达上空有卷云和无卷云的大气回波信号的对比求解，得出间歇性卷云的消光后向散射比，并与其他方法进行了对比分析，指明了该方法的可靠性和局限性。

Lidar ratio of cirrus cloud has been attracted much attention as it is one of the most important parameters to study the optical properties of cirrus cloud. A new method has been introduced to deriving the lidar ratio of discontinuous high-altitude thin cirrus cloud by using the data from Mie scattering lidar measurements. The lidar ratio of discontinuous thin cirrus has been obtained after comparing the backscatter signal of the atmosphere observed in the condition of with and without cirrus in the usual days. The reliability and the disadvantage are also discussed by comparing with other methods.