Abstract: Cold tolerance at the booting stage of recombinant inbred lines (RIL) were analyzed undert indica and japonica rice cropping regions by using Kunmingxiaobaigu and Dalizaoxian, Yunnan rice landrace, and their F7 and F8 generation. The results showed that (1) plant height, internode length No.1, panicle length and pikelets per panicle show the characteristic of quantitative traits. (2) There is the clear difference on correlation of some traits between indica and japonica rice regions, which shows plant height and seed setting rate etc. traits at cold-cool jaopnica rice cropping regions. On the contrary, panicle exsertion and four trait of panicle of RIL were significantly correlated at 5% or 1% level of at high temperature indica region. (3) Genetic analysis showed that there were major gene affecting the panicle exsertion and seed setting rate of low or high temperature sensitive, a lot of weaker plants with cold tolerance have relatively stronger heat tolerance.