The relationships among reflectivity, velocity and spectrum width of stratiform cloud are simulated, and the availability of cloud radar data are analyzed. The reflectivity, velocity and spectrum width observed by cloud radar in vertical observation model are used to retrieve the liquid water content and the size distribution in stratiform cloud under the assumption of neglecting the air vertical speed and turbulence. The results show that the relationships among reflectivity, velocity and spectrum width observed by 8 mm cloud radar are similar to simulated values. The mean drop size, toll drop number and liquid water contend have obvious variations from cloud top to reflectivity center. The increase of reflectivity is due to the increase of drop size. The microphysical parameters retrieved by cloud radar have similar range with that by aircraft.