Motivation-driven mating is a basic affair for the maintenance of species. However, the underlying molecular mechanisms that control mating motivation are not fully understood. Here we report that NRG1-ErbB4 signaling in the medial amygdala (MeA) is pivotal in regulating mating motivation. NRG1 expression in the MeA negatively correlates with the mating motivation levels in adult male mice. Local injection and knockdown of MeA NRG1 reduce and promote mating motivation, respectively. Consistently, the knockdown of MeA ErbB4, a major receptor for NRG1, and the genetic inactivation of its kinase both promote mating motivation. ErbB4deletion decreases neuronal excitability, whereas chemogenetic manipulations of ErbB4-positive neuronal activities bi-directionally change mating motivation. Last, we identify that the effects of NRG1-ErbB4 signaling on neuronal excitability and mating motivation rely on hyperpolarization-activated cyclic nucleotide-gated 3 (HCN3) channels. This study reveals a critical molecular mechanism for regulating mating motivation in adult male mice.