Crop biomass is one of the key indicators not only in crop condition monitoring, but also in crop production estimation. With the development of 3S technology, it is feasible to estimate crop biomass at large scales with remote sensing. In the present paper, the researches on crop biomass estimation models with remote sensing were reviewed, and the methods of crop biomass estimation were classified into six categories according to their differences in data source and methodology. The advantages and deficiencies of each method were discussed and analyzed. Finally, the paper presents the prospect of the methods of crop biomass estimation.