WCM (water cloud model) developed in 1978 was proved useful for vegetation parameters estimation. However, its no sense of polarization dependence limited its application with quad-polarimetric data. In this study, we developed polarimetric water cloud model (PWCM) and applied to quad-polarimetric GF-3 data for winter wheat biomass estimation. (HH−VV)/HV,(HH+W) /HV, HH/VV and VOL (volume scattering from Freeman Durden decomposition)/(ODD (odd scattering or surface scattering)+DBL (double bounce scattering)) were used as surface volume ratio parameters and provided in the developed PWCM. The results showed the effectiveness of developed PWCM for crop biomass inversion. Among all the parameters, (HH−VV)/HV showed best performance for winter wheat biomass inversion. The RMSE is 157.58 g/m2, the relative accuracy is 63.88.