Abstract: Sea surface salinity from Argo and Aquarius data is used to explore seasonal pathways for Arabian Sea highsalinity water (ASHSW) intrusion into the Bay of Bengal (BOB). The data show that there are three types of, i.e. summer, winter and spring, ASHSW intrusions into the BOB. In summer (i.e. July to October), ASHSW intrudes into the BOB via the western bay mouth with a net volume transport of 1.53 Sv. In winter (December to next January) and spring (March to May), ASHSW intrusions occur in the central and eastern bay mouths with relatively weaker net volume transports of 0.39 Sv and 0.41 Sv, respectively. The intrusion branch of the Southwest Monsoon Current (SMC) is the main factor transporting ASHSW into the BOB in summer. The fall Wyrtki Jet raises the sea level off the coast of Sumatra, resulting in high sea surface high in the eastern bay mouth and a positive (i.e. westward) sea surface high gradient. Then, this westward zonal pressure gradient force drives the northward geostrophic current, which ultimately induces the intrusion of ASHSW into the BOB in winter. The spring Wyrtki Jet is also a major cause for the intrusion of ASHSW during this period under almost the same dynamics in winter.