Neck linker binding to motor domain is the force generation process of kinesin.It depends on the various non-bonding interactions in neck linker and motor domain.In preview papers, there is a backbone H-bond between ASN334 in neck linker and GLY77 in motor domain, which called center H-bond.This H-bond is surrounded by three amino acids which form an amazing strength structure called the ASN latch with hydrophobic interaction.It is find that the high strength of the ASN latch comes from the cooperation of between hydrogen bonds and hydrophobic interactions.The center H-bond is protected by hydrophobic amino acids while the existence of the center H-bond limits the distances of the former by thermal motion.The hydrophobic interaction of three hydrophobic amino acids becomes possible by the events mention above.By mutating the hydrophobic amino acids in molecular dynamic simulation, the strength of the ASN latch decrease and the center H-bond becomes so unstable that likely to break.The center H-bond breaks quickly under a small strain.