A new method of surface chemical modification of nano-SiO2 is proposed in this paper. In the presence of catalyst, the active hydroxyl groups on the surface of nano-SiO2 reacted with AB2-type monomer (N, N-dihydroxyethyl-3-amino methyl propionate) by one-step polycondensation. And the product's Fourer transform infrared (FTIR) graphs and transmission electron microscopy(TEM) images proved that hyperbranched poly (amine-ester) was grafted on nano-SiO2 surface successfully. Results show that the modified nano-SiO2 exhibits excellent dispersion and stability in some solvents such as alcohol and chloroform.