In this paper, based on analyses of Devonian-Carbonifous sediments of the two flacks of the Mianxian-Lueyang zone, it is regarded that the two flanks of the Mianxian-Lueyang zone belong to the South China palaeontological geographic region. In terms of sedimentary facies, sedimentary formation, and filling sequence, the south flank is much the same as the north one in the Mianxian-Lueyang zone. Both of them are characterized by carbonate + clastic formation of shallow sea facies and filling sequence of transgression type. Secondly, the so called Mianxian - Lueyang ophiolite zone is doubted in this paper. Neither the assemblage of rocks nor the match of geological periods supports the idea that ophiolite serves as relics of an ocean basin separating continental blocks. Moreover, the limited distribution of ophiolite does not support the above-mentioned viewpoint, either. Thirdly, comparison of the Mianxian-Lueyang zone with a typical suture zone shows that the Mianxian-Lueyang zone lacks aspatial match relationship of geological bodies inside and on the two flanks of a typical suture, such as trough-arc-basin system, subduction complex and foreland basin. Furthermore, according to relative geochemical and geophysical data, during the period from Devonian to Triassic there was no ocean basin separating continental blocks,and no suture zone was built up during the Indosinian movement along the Mianxian-Lueyang zone. Therefore, it is proposed that the Mianxian-Lueyang zone was a continental within-plate rift from Devonian to Carboniferous. Since the Indosinian movement, the zone has been a tectonic melange zone, which has undurgone multphase tectonic movements. In intracontinental orogeny, large-scale continental crust subducted probably took place along the zone.