Abstract: The progress of the research on the mixing of high viscous fluid in recent 20 years is reviewed，presenting the choice of experimental fluids，description of rheology and evaluation criteria of mixing performance. Mechanically stirred equipment used in the high viscous fluid mixing includes vertical，or horizontal shaft，and single，or dual shafts. The investigation results on various equipment are introduced. Further investigations should be performed in the optimization of agitators and mixing performance in coaxial and biaxial agitation，vertical and horizontal mixing tanks. Numerical simulation of high viscous fluid mixing by using the computational fluid dynamics (CFD) approach is still under further study.