Improvement of chilling tolerance is a key strategy to face potential menace from abnormal temperature in rice production, which depends on the signaling network triggered by receptors. However, little is known about the QTL genes encoding membrane complexes for sensing cold. Here,Chilling-tolerance inGengdao/japonica rice1(COG1) is isolated from a chromosome segment substitution line containing a QTL (qCS11-jap) for chilling sensitivity. The major geneCOG1is found to confer chilling tolerance injaponicarice. In natural rice populations, only the haplogroup1 encodes a functional COG1. Evolutionary analysis show thatCOG1originates from ChineseO. Rufipogonand is fixed injaponicarice during domestication. COG1, a membrane-localized LRR-RLP, targets and activates the kinase OsSERL2 in a cold-induced manner, promoting chilling tolerance. Furthermore, the cold signal transmitted by COG1-OsSERL2 activates OsMAPK3 in the cytoplasm. Our findings reveal a cold-sensing complex, which mediates signaling network for the chilling defense in rice.