The influences of spin fluctuations on the magnetization M and thermal expansion for La(NixAl1−x)13 amorphous alloys have been investigated. The spontaneous magnetization obeys a M2–ξT4/3 relation and the coefficient ξ is concerned with the dynamical spin fluctuation spectrum. The spontaneous volume magnetostriction in the ferromagnetic state appears due to the thermal variation of the local spin amplitude. The change in the linear thermal expansion coefficient in paramagnetic temperature regions is caused by the saturation of amplitude of the spin fluctuations.