The air flow analysis of considering heat-generating components in a three dimensional desktop computer was investigated in this paper. A well known computational fluid dynamics (CFD) was employed to simulate the desktop computer chassis enclosure. The CFD software that used is the ANSYS Workbench and ANSYS CFX 10.0. The parameters are focused on the outlet air velocity and inlet velocity. The CFD analysis result will confirm by the experiment. This paper describes the methodology of CFD analysis for the desktop computer design, and describes the experimental details to predictions. The comparison result for both methods will be discussed in this paper.