  We study the effect of the solitonic degrees of freedom in string cosmology
following the line of Rama. The gas of solitonic p-brane is treated as a
perfect fluid in a Brans-Dicke type theory. In this paper, we find exact
cosmological solutions for any Brans-Dicke parameter $\omega$ and for general
parameter $\gamma$ of equation of state and classify the cosmology of the
solutions on a parameter space of $\gamma$ and $\omega$.
