Abstract: The current progress of research into plant disease-resistance genes (R-genes) was reviewed. We discussed their resistance mechanisms and signaling. According to a conservative structure, plant R-genes could be classified into five groups: NBS-LRR, eLRR-TM, eLRR-TM-pkinase, STK and others. R-genes with NBS, pkinase or eLRR play an important role in plant disease resistance by their respective pathways, although their structures were different.