The present study has numerically investigated two-dimensional induced-charge electroosmosis flows in a microchannel with conducting/Janus cylinder to understand its performance of pumping and mixing.For the study, numerical simulations are performed by employing the Nernst-Planck equation for the ionic species and the Poisson equation for electric double layer with arbitrary Debye thickness and electric potential, together with the traditional Navier-Stokes equation.Its found there are four large circulations around the conducting cylinder and the total flux in the microchannel is zero; there are two smaller circulations around the Janus cylinder and they are compressed to wall,and the bulk tlux has a parabolic relation with applied electric field.These conclusions may be helpful to the design of mixer and pump in microfluidics.