Abstract: In the nature, mass transfer is dominated by shear dispersion when the shear effects in flow are very strong. It is G.I. Taylor (1953) who first investidated such problem and gotten a formula for laminar flow.Two exceptions to the Taylor's theory are early stage of dispersion process and shear dispersion with boundary absorption, which the Smith(1981, 1983) gave the description by a delay diffusion equation. Liu(1994) described the two dimensional contaminant dispersion with memory properties. In this pap...