Abstract: The recent research about the model of activating signaling pathways in the natural killer (NK) cells allows us to shed new light on how NK cells function. Binding of activating receptors to its ligand(s) will lead to activation signals to proceed, resulting in activation of SLP-76, WASP and PI3K. Activated SLP-76 will recruit and bind many downstream molecules including PLC-γ, Itk and Vav, whereas activated WASP will recruit and bind Grb-2, Vav, WIP, Arp2/3 and Cdc42-GTP, among others. Nck, which binds to both SLP-76 and WASP, will transport the multimolecular signaling complex to cytomembrane where activated Arp2/3 and PLC-γ will partake in actin polymerization, cytoskeletal remodelling, NFAT gene transcription and cytokine secretion. Activation of PI3K will lead to granule polarization through Rac/PAK/MEK/ERK pathway.