With the group of the TcLr41 seedling cDNA as the tester and the corresponding group of the Thatcher seedling cDNA as the driver,the suppression subtractive hybridization(SSH) was performed.A subtractive library which contains 2544 clones was constructed.The PCR results of random recombinant plasmids showed that the length of inserts ranged mainly from 200bp to 1000bp,which indicated that the subtractive cDNA library was qualified for the following research.Through gene function analysis,some genes,such as,catalase gene,rust resistance gene,blue copper-binding protein gene,ring zinc finger protein gene,stress responsive protein gene,etc.,were supposed to be the differential expression genes related to Lr41.