In this paper, we discussed the effect of couple-stress micro on the polar fluid layer heated from below in the presence of varying gravitational field in a porous medium with suspended particles. The dispersion relation has been analyzed using normal mode, it is found that the medium permeability and suspended particle have destabilizing effect. The couple-stress parameter, coupling parameter, heat conduction parameter and micro-polar coefficient have stabilizing effect. The sufficient condition for the non-existence of over stability has also been obtained.