Soil moisture is an important component of soil

and plays an important role in materials and energy exchanges between earth and atmosphere. It is also the basic parameter of crop growing and crop yield forecast. With the features of observing large area synchronously

timely

and economically

remote sensing technique makes dynamic soil water monitoring possible. This paper briefly summarizes the up-to-date progresses on the developed principle algorithms and methodologies for remote sensing of soil water content

including thermal inertia approach

crop water stress index method

normalized vegetation index scheme

ATNDVI

crop water deficit index method

vegetation condition index scheme

temperature condition index method

temperature/vegetation dryness index approach

hyper spectral remote sensing based algorithm

and microwave remote sensing orientated methodology. The features and feasibility of every discussed algorithm or approach are systematically analyzed

and the future possible prospect of the developing trend on soil moisture monitoring by remote sensing is reviewed.