By making full use of the estimates of solutions to nonstationary Stokes eq
uations and the method discussing global stability, we establish the global
existence theorem of strong solutions for Navier-Stokes equations in arbit
rary three dimensional domain with uniformly C-3 boundary, under the assump
tion that parallel to a parallel to L-2(Omega) + parallel to f parallel to
L-1 (0,infinity;L-2(Omega)) or parallel to del a parallel to L-2(Omega) + p
arallel to f parallel to L-2(0,infinity;L-2(Omega)) small or viscosity nu l
arge. Here a is a given initial velocity and f is the external force. This
improves on the previous results. Moreover, the solvability of the case wit
h nonhomogeneous boundary conditions is also discussed.