We report simple acrylamide polymerization process to prepare nanocrystalline tin dioxide(SnO_2) particles.A small amount of the so-called premix solution(monofunctional acrylamide and difunctional N,N’-methylenebisacrylamide) was mixed with the aqueous solution of Sn~(4+) in certain proportion,and a few drops of ammonium persulfate solution were added as initiator.When homogenized by magnetic stirring and heated to about 70℃,the mixed solution became a gel.This hydrous gel was directly decomposed by thermal treatment,resulting in obtaining rutile crystalline SnO_2 particles with a narrow size distribution typically in the range of 20 nm～40 nm. We report simple acrylamide polymerization process to prepare nanocrystalline tin dioxide (SnO 2) particles. A small amount of the so-called premix solution (monofunctional acrylamide and difunctional N, N’-methylenebisacrylamide) was mixed with the aqueous solution of Sn ~ (4+ ) in certain proportion, and a few drops of ammonium persulfate solution were added as initiator. When homogenized by magnetic stirring and heated to about 70 ° C, the mixed solution became a gel. This hydrous gel was directly decomposed by thermal treatment, resulting in rutile crystalline SnO 2 particles with a narrow size distribution typically in the range of 20 nm ~ 40 nm.