The super typhoon “Saomai” (No.0608) landed at the coast of Cangnan County，Zhejiang Province on 10 August 2006， with the maximum wind force being up to 17 in the vicinity of its center and the central pressure being 920 hPa． It is the most powerful typhoon landed in Mainland China since 1949. A great deal of researches reveal that the weak environmental vertical wind speed shear, high sea surface temperature (SST), strong divergence at the upper level and remarkable vorticity near the center of Saomai, etc., play important roles in the rapidly intensifying process. Some researchers conducted invaluable work such as observational study, numerical simulation, and the causes of sudden intensity increase, etc. A review is made of the previous achievements, and the problems existing presently in this field are discussed.