  We study the thermal properties of QCD in the presence of a small quark
chemical potential $\mu$. Derivatives of the phase transition point with
respect to $\mu$ are computed at $\mu=0$ for 2 and 3 flavors of p-4 improved
staggered fermions on a $16^3\times4$ lattice. Moreover we contrast the case of
isoscalar and isovector chemical potentials, quantify the effect of $\mu\not=0$
on the equation of state, and comment on the screening effect by dynamical
quarks and the complex phase of the fermion determinant in QCD with
$\mu\not=0$.
