This excperiment was conducted to investigate relation on seed dormancy and vi-viparous germination with sucrose content, fatty acid composition and abscisic acid content of rice seeds. The following results were obtained by this experiment. Sucrose content of brown rice harvested at 20 and 40 days after heading was higher in Japonica and Sare type varieties than in Tongil and Indica type rices. Positive relationship was found be-tween sucrose content of brown rice and viviparous germination rate of rice varieties tested.J aponica and Sare type rice varieties showed low proportion of oleic acid and higher proportion of linoleic acid in brown rice harvested at 20 and 40 days after heading than Tongil and Indica rices tested. Viviparous germination was negatively correlated with the proportion oleic acid and positively with that of linoleic acid. Abscisic acid content in hull of rice seeds stored for 30 days at 25/15$^{circ}C$ fluctuation temperature condition was decreased more rapidly than 4$^{circ}C$, and Japonica varieties tested showed lower con-tent of abscisic acid in rice hull than Tongil and Indica varieties used.