  We study the strong solution to the 3-D compressible Navier--Stokes
equations. We propose a new blow up criterion for barotropic gases in terms of
the integral norm of density $\rho$ and the divergence of the velocity $\bu$
without any restriction on the physical viscosity constants. Our blow up
criteria can be seen as a partial realization of the underlying principle that
the higher integrability implies the boundedness and then eventual regularity.
We also present similar blow up criterion for the heat conducting gases.
