Abstract：Differential Display Reverse Transcript Polymerize Chain Reaction (DDRT—PCR)was applied to study gene expression in heat-tolerant variants N1-2-1 and it’s mother plants N1 under heat stress. The results show that 1419 bands were amplified from 40 pairs of primers in the two clonal lines, 100 of them appear different obviously between the two clonal lines and which accounted for 7.2% , 41 of 100 bands which came from heat-tolerant variants N1-2-1. The northern blot results showed that 6 segments of the 41 were confirmed to express only in the N1-2-1, those fragments were then cloned into vectors for sequencing, sequence analysis through Internet Blast searching showed that 2 of them related to response of rice and potato under heat stress respectively, one of them related to anthocyanin 5-aromatic acyltransferase , and the other 3 fragments（DF2、 DF5、DF6） were novel cDNA fragment.
