Abstract:A brief review is made of the characteristics of intraseasonal oscillation (MaddenJulian Oscillation) and ENSO (ElNino/Southern Oscillation), as well as the relationships between them.The modulation impacts of MJO and ENSO on the tropical cyclone (TC) activities are summarized, involving the impact on TC formation, intensity, track, lifespan, etc. The respective dynamical mechanisms, the problems and prospects in this field are also discussed briefly as well.