A joint French‐Taiwanese cruise in May and June 1996 on the French research vessel L'Atalante has provided detailed structural images of the sea floor east and southwest of Taiwan. High quality swath bathymetry (see Figure 1) and seismic reflection profiles collected in southeastern and southwestern offshore areas near Taiwan will increase our understanding of how the Luzon Arc is deformed by its collision with the Chinese passive margin and how the Manila Trench connects with the deformation front on Taiwan. The data collected off the eastern coast of Taiwan will elucidate the nature of the plate boundary between the Ryukyu subduction zone and the Taiwan mountain belt and reveal the mode of back arc opening in the Southern Okinawa Trough. The investigations will contribute to understanding the processes of accretion of an arc to a continent prior to the ultimate collision between continents.