Ⅲnitride wide bandgap semiconductors, such as gallium nitride (GaN) and aluminum nitride (AlN), are the key materials for the development of shortwavelength optoelectronic devices, as well as highfrequency and highpower electronic devices. Due to the lack of highquality and lowcost homogeneous GaN and AlN substrates, nitride semiconductors are mainly realized by means of heteroepitaxy, especially the large latticemismatched heteroepitaxy, resulting in high defect density and huge residual stress in the epilayers, which have become the key bottlenecks in the development of deep ultraviolet light emitting devices and power electronic devices, and other nitride semiconductor ones. In this paper, the research history of the large latticemismatched heteroepitaxy of nitride semiconductors by means of metal organic chemical vapor deposition (MOCVD) is first briefly introduced. Then, the research progress on the MOCVD epitaxial growth and ptype doping of AlN and high Al composition AlGaN on sapphire substrate, as well as the MOCVD epitaxial growth and defect control of GaN and its heterostructures on Si substrate in Peking University are demenstrated. Finally, the current challenges and developing trends on the large latticemismatched heteroepitaxy for Ⅲnitride wide bandgap semiconductors are reviewed and expected.