We put forth a project, that is: using the backscatter technique to realize adaptive long-distanceHF broadcasting system in order to improve tke quality of HF broadcasting. Then, we analyze errors of thesystem due to the deviation of the ionospheric parameters’ prediction From the analysis, we draw the conciusion that our project is feasible. In addition, we point out that we can use frequency-spreading and information-coding technique to acquire more c1ear lonograms. We als0 offer a judgment on how to choose the control propagation mode on condition of multihop and the existence of more than one propagation mode on thesignals’ path.