The air-side heat transfer and pressure drop characteristics of multi-louvered fin arrays are concerned using computational fluid dynamics (CFD) technique. Three types of three-dimensional (3-D) models, namely, full-louvered model, flat-landing region model and transition region model are established and calculated with air side ReLP of 100-600. Result comparison of different models with the experimental data demonstrates that, transition region model performs the least mean deviation of fanning friction factor f in the fin arrays. Predicted f factors with full-louvered model and flat-landing model are overestimated to some extent. For Colburn heat transfer j factor, computational results with full-louvered model are still overpredicted with a mean deviation of 20.42%, while mean deviations of transition region models with different transition-region widths are below 10%. Further study also indicates that different thermal conductivities of the aluminum fin and transition-region width for transition region model have a slight influence on the heat transfer performance. Although flat-landing model and transitional region can fairly accurately predict j factor with adjacent error, transition region model is more reasonable for real geometry of multi-louvered fins.