The ophiolite is the direct evidence to restore the oceanic evolution, and it is used to identify the convergence boundary of the plates. Compared with ophiolite, the matrix of ophiolite records more information about the evolution of oceanic plates. In order to understand the tectonic implications for matrix of ophiolitic mélange, the Mesozoic Paleo- Tethys Ailaoshan- Song Ma- Song Chay suture zone located in the North Vietnam- Southeast Yunnan region acts as an ideal study area. On the basis of the structural geology, we reviewed previous zircon U- Pb dating and Lu- Hf isotopic analyses on the detrital zircon from the Ailaoshan- Song Ma ophiolitic mélange. Accordingly, we subdivide the matrix of the Ailaoshan- Song Ma ophiolitic mélange into three parts (M1, M2, and M3). M1 is mainly located in the middle segment of the Ailaoshan- Song Ma belt. It shows the age peaks of 440 Ma and 960 Ma with εHf(t) values of -196~+103, indicating the affinity of the Indochina block. M2 is mainly located in the NW segment of the Ailaoshan- Song Ma belt, showing a dominant age peak of ~260 Ma. Particularly, it has εHf(t) values of -189~+81, likely sourced from the ELIP on the South China block. M3 is mainly located in the SE segment of the Ailaoshan- Song Ma belt, showing the peaks at ~250 Ma, 440 Ma, and 960 Ma with εHf(t) values of -119~+101; its main provenance is the magmatic arc on the Indochina block. The detrital zircons of the Song Chay ophiolitic mélange matrix are mainly from the subducting South China plate, with only a small part from the overlying Indosinian plate. The above- mentioned heterogeneity of the ophiolitic mélange indicates the change of detrital zircon provenances during the closure of the ocean basin. Importantly, we argue that the detrital material is mainly from the passive continental margin of the subducted SCB plate, while does not invariably come from the overriding Indochina plate. It likely implies that the eastern Paleo- Tethys was a limited oceanic basin instead of a vast ocean.