There are some limitation related to measuring vegetation biomass of conventional approaches such as lower spatial resolution. A method of retrieving vegetation biomass based on GPS satellite SNR was studied in this paper. The direct component was obtained by polynomial fitting and removed from SNR, by which the reflected component was extracted and the amplitude characteristics was analyzed. The normalized amplitude was calculated by the ratio of the amplitude of vegetation and bare soil, and compared with the rainfall and NDVI data in effective reflected area. The results indicated that the normalized amplitude was strongly correlated with NDVI. It is a promising approach to monitor vegetation biomass with high spatiotemporal resolution.