As a model of the now through the coronary artery, the laminar flow through a two-dimensional channel that oscillates toward a transverse direction has been studied numerically. In this calculation, the moving boundary problem was transformed into the fixed boundary problem using the coordinate transformation method, and the fully implicit bite difference method was used to solve the mass and momentum conservation equations. The calculated results are summarized as follows. (i) The particle trap extended over a long time is not generated by the transverse oscillation of the channel. (ii) The transverse oscillation of the channel has an effect of Battening the distribution of shear rate in the downstream side of the oscillating region. (iii) This numerical calculation method is effective to understand the now pattern through the oscillating channel.