The characteristics of THz-band cloud profiling radar experimental results are analyzed. Based on the optimal estimation theory, the characteristic of liquid cloud microphysical parameters, including effective radius, liquid water content, number density and distribution width parameter are retrieved. The observed cases are strat or stratocumulus, which belong to low cloud and have stable cloud structure, with relatively weak radar reflectivity at cloud bottom and top. The retrieval results are basically consistent with the statistical values of cloud microphysical parameters in the relevant literature. The effective radius is larger in the region with larger radar reflectivity, and the liquid water content is higher. The number density shows a trend of decreasing with height.