A cross-flow fan having forward curved blades relatively produces higher dynamic pressure at low rotating speed because a working fluid passes through an impeller blade twice. Most of this dynamic pressure is transferred to the static pressure in a rearguider and a stabilizer as a scroll in the centrifugal fan. The effect of a rearguider and a stabilizer on the performance of a cross-flow fan is higher than that of the impeller. Therefore, it should be considered how the shape of a rearguider and an exit duct affects on the performance and the flow fields. The purpose of this study is to investigate the reciprocal relation to the flow field and performance among the design parameters. Two-dimensional, unsteady governing equations are solved using FVM algorithm, sliding grid system and standard $k-{varepsilon}$ turbulence model. Velocity profiles with various parameters are depicted. Furthermore, the meridional velocity profiles around the impeller are plotted at fixed rotating speed and design flow rate.