KH-570 coating nanosized Antimony Doped Tin Oxide (ATO) particles were obtained by the ATO functionalized with silicon coupling agent KH-570 in the mixed media of ethanol and deionized water. The surface structure and the property of the obtained nanosized ATO particles were characterized by a series of tests such as FTIR, XPS, TG, TEM, etc. The grafted ratio of KH-570 and the surface modified mechanism of ATO with KH570 were further discussed here. Results revealed that about 7.36-7.73wt% of KH-570 had been successfully grafted onto the surface of ATO. The lipophilicity and the dispersibility of the modified nanosized ATO particles were significantly improved which could be dispersed stably in n-butanol for more than 100h. The mechanism illuminated a network structure silicon coupling agent layer was formed on the surface of the ATO particles during the grafting reaction with the help of the supersonic wave, which gives a good performance of the lipophilicity and the dispersibility of these obtained nanosized ATO particles.