Abstract: Great progress has been made in studies of rice somaclonal variation. Many somaclonal mutants with good qualities ,such as resistance for diseases and adverse environmental conditions ,good grain qualities and dwarf plant type, have been successfully obtained .Genetic analysis on these mutants indicated that most of the mutations are controlled by 1 or 2 pairs of genes. It is showed that the frequencies of occurrence of somaclonal variationin in rice is related with the gonotype, character, subculture period, tissue culture manner. Also some inherent mechanism seems to be involved in it. Point mutation and insertion of retrotransposons are probably two important reasons for somaclonal variation in rice.