The present invention discloses an inorganic/organic mixed component (I/O) dispersant and applications thereof, which is primarily applied to dispersing nanoparticles of metal oxides. The I/O dispersant of the present invention can be a composite of inorganic clay and an organic surfactant, a composite of inorganic clay and polyoxyalkylene-amine, or a composite of inorganic clay, polyisobutylene succinic anhydride (PIB-SA) and hydrochloric acid salt or tetraalkyl quaternary salt of polyoxyalkylene-amine, or fatty amines. By mixing with the I/O dispersant of the present invention, nanoparticles of a metal oxide can be uniformly dispersed without aggregation particularly at high solid content. The dispersion has a lower viscosity and is relatively stable in storage even at high temperature.