estimating the regolith depth from brightness temperature (TB) measured by a multi-channel radiometer at 3GHz, 7.8GHz, 19.35GHz and 37GHz. To establish the accurate microwave radiation or scattering model of lunar surface, firstly we need to determine an accurate model of dielectric constant of lunar regolith. However, until now there is no model of dielectric constant suitable for microwave band between 3GHz–37GHz.In this paper, we extract the normalized temperature deviation τ from CE-1 TB data, which filter out the diurnal variation and the impact of latitude. Then we established a new dielectric constant model for microwave band, through analyzing the different relationship that between τ and the content of iron and titanium. The parameters in the model are inverted by comparing the TB measured and the TB calculated. At last, we compared the proposed dielectric constant model with the measured results of lunar regolith samples.