Hibernating mammals survive winter season by periodically lowering their body temperature down to the freezing point. The hibernation regulation therefore means a great challenge to their cardiovascular systems. To elucidate the underlying adaptation, we compared the excitation-contraction (E-C) coupling in ventricular cardiomyocytes from hibernating (HGS) and awake (AGS) ground squirrels. Whole-cell voltage clamp showed that the current through L-type Ca2+ channels (LCC) was down-regulated in HGS compared with that in AGS. However, simultaneous recording of fluo-4 fluorescence revealed that the Ca2+ transient triggered by LCC current was not decreased. The gain of Ca2+-induce Ca2+ release (CICR) was thus enhanced remarkably in hibernation. To seek the molecular mechanisms, we investigated the intermolecular signaling between a single LCC and ryanodine receptors (RyRs). Loose-patch confocal imaging showed that the LCC-RyR coupling exhibited shortened latency and increased chance-of-hit in HGS. The enhancement of LCC-RyR signaling efficiency was not attributable to any difference in the Ca2+ contents in the sarcoplasmic reticulum (SR). Realtime PCR and western blot both revealed that the expression of junctophilin-2, a protein anchoring the RyR-residing SR to the LCC-residing T-tubules, was up-regulated in HGS. These data indicated hibernation comes with a regulation that enhances the efficiency of E-C coupling in heart cells. This molecular and functional remodeling is exactly opposite to that occurring in failing hearts, and thus provides an ideal research model for seeking new strategies against heart failure.