Abstract: The western North Pacific subtropical high (WNPSH) is an important circulation system which impacts the East Asian summer climate. The interannual variability of WNPSH is modulated by tropical air-sea interaction. In order to make it clear which oceanic regions are crucial to the interannual variability of the WNPSH, the relevant research progresses in the past decades are reviewed. Based on the review, five oceanic regions are ascertained to be responsible for the interannual variability of the WNPSH in summer, including the equatorial central-eastern Pacific Ocean, tropical Indian Ocean, the subtropical western North Pacific, the vicinity of the maritime continent and the tropical Atlantic Ocean. The mechanisms how the sea surface temperature (SST) anomalies (SSTA) in these regions impact the WNPSH are elaborated. The formation mechanisms for the SSTAs in these five regions are discussed. Strengths and weaknesses of the climate models in simulating and predicting the WNPSH are also examined and documented. Finally, the key scientific problems reserving further study are proposed.