  The transport relaxation time $\tau (P)$ and the mean free path of
magnetoexcitons in single and coupled quantum wells are calculated ($P$ is the
magnetic momentum of the magnetoexciton). We present the results for
magnetoexciton scattering in a random field due to (i) quantum well width
fluctuations, (ii) composite fluctuations and (iii) ionized impurities. The
time $\tau(P)$ depends nonmonotonously on $P$ in the case (ii) and in the cases
(i), (iii) for $D/l$ smaller than some critical value ($D$ is the interwell
separation, $l=\sqrt{\hbar c/eH}$ is the magnetic length). For $D/l\gg 1$ the
transport relaxation time increases monotonously with $P$. The magnetoexciton
mean free path $\lambda (P)$ has a maximum at $P\ne 0$ in the cases (i), (iii).
It decreases with increasing $D/l$. The mean free path calculated for the case
(ii) may have two maxima. One of them disappears with the variation of the
random fields parameters. The maximum of $\lambda (P)$ increases with $H$ for
types (i,iii) of scattering processes and decreases in the case (ii).
