Sn-In2O3 nanoparticles were synthesized by Sol-Gel method and dispersed steady Sn-In2O3 colloid solution was gained. Sn-In2O3 nanoparticles are body-center cube ferromanganese mine structure proved by XRD. And they are spheres and 15~25nm studied by HRTEM. The average size of nanoparticles is 21.7 nm with a narrow width 10.8nm measured by granularity instrument. Zeta potential is +33.4mV which means that there are very strong electrostatic repulsion to prevent the bird nesting of Sn-In2O3 nanoparticles.