In order to improve inversion accuracy for soil moisture and enhance the research on quantitative soil moisture, a method combining finite element with Genetic Algorithms is proposed. Affected by precipita-tion, irrigation, wind speed, and so on, there exist complex material and energy exchanges on the interface of atmosphere and soil, which lead to very complex boundary conditions of coupled moisture and heat flow equation. Then, Genetic Algorithms are applied to calculating the boundary conditions of the equation. Sur-face initial condition of the equation is obtained by remote sensing technique. Finally, the finite element method is applied to solving the equation. Thus, monitoring of soil moisture is fulfilled. The tested results show that the method is feasible and satisfactory by comparing with observed data of soil temperature and soil moisture.