The direct simulation Monte Carlo (DSMC) method is used to solve the 2-D steady micro-channel flows at slip flow regime and transition flow regime with Knudsen number of 0.045 and 0.108. In the DSMC method, hundreds of thousands of simulated particles are used to simulate the flow in micro-channel. The variable hard-sphere (VHS) collision model is used. A new method is proposed to modify the boundary conditions when DSMC is used to solve the low speed flow in micro-channel. The streamwise velocity distributions and nonlinear pressure distribution are obtained. The DSMC results are compared with the analytical results and they agree well each other.