Tropical intraseasonal oscillation （MJO） is the main source of the extended range forecast. The research of the extended range forecast based on MJO is of great significance for the operational forecast. In this paper， the latest achievements of MJO in the prediction of precipitation， temperature and their extreme events， typhoon and monsoon in the extended range and the operational status of major prediction centers in which MJO is used for real-time monitoring and prediction were reviewed systematically. The theoretical support of MJO in the prediction of the extended range was summarized. Finally， the technical difficulties of MJO in the application of the extended range forecast， such as the establishment of forecast objects， the simulation of MJO by the current dynamic model， the physical connection between MJO and meteorological elements， and the evaluation of MJO's influence forecasting were analyzed， and the future development trends of MJO influence forecast in the ensemble forecast， multi-mode integration and strengthening the research on the influence of multiple seasonal oscillations on the weather were also pointed out.