  We investigate whether the baryon asymmetry of the universe is explained in
the framework of the supersymmetric extension of the Standard Model with
R-parity violating interactions. It is shown that the Affleck-Dine mechanism
naturally works via a trilinear interaction $LLE^c$, $LQD^c$, or $U^cD^cD^c$,
if the magnitude of the coupling corresponding to the operator $\lambda$,
$\lambda'$, or $\lambda''$ is sufficiently small. The formation of Q-balls and
their subsequent evolution are also discussed. The present baryon asymmetry can
be explained in the parameter region where R-parity is mildly violated
$10^{-9}\lesssim\lambda,\lambda',\lambda''\lesssim 10^{-6}$ and the mass of the
gravitino is relatively heavy $m_{3/2}\gtrsim 10^4\mathrm{GeV}$. On the other
hand, it is difficult to explain the present baryon asymmetry for larger values
of R-parity violating couplings $\lambda,\lambda',\lambda''\gtrsim 10^{-5}$,
since Q-balls are likely to be destructed in the thermal environment and the
primordial baryon number is washed away.
