Abstract: In the study of orogenic belts，oceanic crust subduction orogenic process and continental crust collision orogenic time are important contents in the study of orogenic belts around the world. Molasse is one of the key factors to study oceanic crust subduction orogeny and continental crust collision orogeny in orogenic belt.Through the in-depth study of the orogenic belt in Heilongjiang Province，it is believed that the theoretical significance of the study of Motolite is to reconstruct the mountain history from the perspec⁃ tive of the orogenic belt，that is，Motolite can not only limit the closing time of the ocean basin at the edge of the block，but also can invert the recessional subduction orogenic stage of the ocean crust in the orogenic belt (the stage of the ocean-land conversion).The analysis results have certain guiding significance for study⁃ ing the process of moralite and oceanic crust subduction orogenesis (the process of land-ocean conversion).

Key words: orogenic belt, oceanic subduction orogenic molasse, continental crust collision orogenic molasse