The formation of C-C bond in the construction of complex molecules remains one of the foremost challenges in organic synthesis. The advance of transition metal catalysis has provided organic chemists with a broad range of new tools to forge C-C bonds. Diazo and diazonium salt compounds play an important role in the development of organic synthesis. Both of them could be decomposed by transition metal catalysis and applied in the C-C bond formation. In this review, the transition metal-catalyzed cross coupling reaction involving diazo and diazonium salt compounds is described in detail.