The Donaldson--Thomas invariants count stable coherent sheaves on Calabi--Yau 3-folds, and their rank one theory is related to Gromov--Witten invariants. Around 2008-2010, Bridgeland and myself studied wall-crossing formulas of rank one DT invariants and proved several properties, e.g. DT/PT correspondence, rationality. In this talk, I explain that the similar properties also hold for higher rank DT invariants.