Aeromagnetic reconnaissance has revealed that the EW trending Yarlung Zangbo River aeromagnetic anomaly zone, 1400 km in length, is composed of two linear anomaly zones respectively in the north and in the south. It is also considered that it results from two ophiolite belts emplaced along the Yarlung Zangbo River suture zone, with the northern belt playing the dominant role. This is to say that the Yarlung Zangbo River suture zone is comprised of two ophiolite belts instead of one belt as considered by previous geologists. The aeromagnetic anomaly zone is in essence the objective reflection of the existence of the Yarlung Zangbo River suture zone. It not only provides relatively typical magnetic field model for the recognition of the suture zone, but also supplies new grounds to the probable existence of two opening closing processes in the evolution of the Neo Tethys Ocean.