  We construct thermodynamics of the one-dimensional supersymmetric {\it t-J}
model with the $ 1/\sin^2$ interaction and hopping. The thermodynamics is
described exactly in terms of free spinons and holons obeying Haldane's
fractional exclusion statistics at all temperatures. Moreover, at low
temperatures the semionic spinons and holons decouple resulting in the
spin-charge separation in thermodynamic properties. We obtain explicit results
for the spin and charge susceptibilities and specific heat, and interpret them
in terms of the fractional exclusion statistics. Extension to the
multi-component {\it t-J} model shows that the excitations obey either
fractional statistics for g-ons with partial polarization of components, or the
parafermionic one without polarization.
