Abstract: Aiming at the important scientific problem of the location and tectonic evolution of the northeast micro-block group in Northern China，based on the ocean-land conversion and continental dy⁃ namics theory，the types and tectonic environments of ophiolite in the erguna-Songnen block are identified by systematic analysis of the material composition of Xinlin-Tayuan-Xinglong subduction accretion com⁃ plex belt of Neoproterozoic to Early Cambrian and Nenjiang-Heihe subduction accretion complex belt of Early Carboniferous，and the types and tectonic setting of ophiolite in subduction accretion complex zone are identified.The study results show that：The ophiolite types of neoproterozoic Xinlin-Tayuan-Xinglong subduction accretion complex mainly include SSZ type ophiolite-niobium-rich basic volcanic rocks，mantle plume type ophiolite-ultramafic rock and gabbro assemblage，and ophiolite ultramafic rock and gabbro as⁃ semblage related to arc-basin evolution.The ophiolite type of the Nenjiang-Heihe subduction accretion complex in the Early Carboniferous is mainly composed of ultramafic and gabitic assemblages related to arc-basin evolution.Based on the material composition of Xinlin-Tayuan-Xinglong subduction accretion complex belt of Neoproterozoic and Early Cambrian，and the spatial distribution of magmatic arcs and re⁃ gional molasite formations of Nenjiang-Heihe subduction accretion complex belt of Early Carboniferous， the oceanic and continental transition process of Neoproterozoic and Early Carboniferous between Erguna Block and Songnen Block is summarized.

Key words: ocean-land transformation, subduction-accretionary complex, tectonic evolution