The effect of different low temperature stress on seed germination was studied with the Japonica Xi-giant embryo-1 rice.The result showed that the restrained degree of seed germination increased with the decrease of temperature in the low temperature stress.when the low temperature is reached 8℃and below,the seed germination rate of Japonica Xi-giant embryo-1 rice was decreased rapidly,and the seedling disease rate was enhanced because it was not restored after low temperature stress treatment.The curves of 50% seedling disease rate and temperature stress indicated that the tolerance temperature of low temperature stress was 9.4℃ to seed germination of Japonica Xi-giant embryo-1 rice.