Abstract-The radar backscatter from complex targets, such as aircrafts and ships, tends to vary rapidly with aspect or time. To describe the radar cross section distribution characteristics of such targets, statistic terms are often used. In this paper, we first give a brief introduction of χ 2 distribution and lognormal distribution model. And complete form of lognormal distribution is proposed which can be used when ratio of mean to median is less than 1 as stealth targets. The significance of the parameters is discussed in detail aiming to find a characterization standard. As an example, the statistic characteristics of the radar cross section data of a stealth aircraft are analyzed with Swerling 1, 3 distribution, χ 2 distribution and lognormal distribution. The applicability of the distributions is shown with error-of-fit and test of goodness of fit.