Calcium waves during fertilization promote the transition from oocyte to embryo. How the fertilizing sperm induces the calcium waves has been explained either by the action of a soluble sperm-delivered factor or by the ligand-receptor interaction between the sperm and the egg. Calcium influx from the extracellular space through a sperm-derived calcium channel was predicted by the calcium conduit model; however, molecular underpinnings for this model have been elusive. Here we show that the sperm-specific plasma membrane calcium-permeable channel TRP-3 (also known as SPE-41) induces a calcium rise in the oocyte upon fertilization in C. elegans. Spinning-disk confocal microscopy and computational image analysis revealed that sperm induce an immediate local calcium rise followed by a propagating calcium wave. This biphasic waveform was recapitulated by a simulation that assumes that the oocyte has calcium-induced calcium release (CICR) machinery. Oocytes fertilized by trp-3 mutant sperm showed a lack of the local calcium rise and a delay in the onset of the propagating wave. Expression of TRP-3 in sperm by sperm-specific expression drivers could rescue the defects partially. Moreover, the stronger the driver activity was, the larger the local calcium rise and the earlier the onset of the propagating calcium wave became. The correlation between the amplitude of the local calcium rise and the delay in the wave onset was again recapitulated by the simulation based on the CICR model. High-speed calcium imaging of the fertilizing sperm cytoplasm revealed that the sperm calcium concentration increases from a resting level, arguing against the bolus introduction of stored calcium from sperm. Moreover, by observing the fertilization between the oocyte whose plasma membrane was labeled with GFP-fused PH domain and the sperm that expresses TRP-3 fused C-terminally with TagRFP-T, we found that fertilization takes place as a single-round direct plasma membrane fusion. These results suggest that sperm-derived TRP-3 channel induces a local calcium rise in the fertilized oocyte. The local calcium rise would then induce a propagating calcium wave probably by the CICR mechanism.