The effects of geometrical parameters of wavy fin and the intensities of longitudinal and transverse vortex on flow and heat transfer characteristics are examined numerically. The results show that under the same Reynolds number, with increasing the fin spacing, the average Nusselt number increases, the flow resistance factor decreases; with increasing the wave amplitude, the average Nusselt number increases, the corresponding flow resistance factor increases, and the intensities of longitudinal vortex and transverse vortex increase; with increasing the wavelength, the average Nusselt number, the flow resistance factor, and the intensity of transversal vortex decrease, whereas the intensity of longitudinal vortex increases. The heat transfer and flow resistance are influenced by geometric parameters and operating conditions, the average Nusselt number or flow resistance is not solely determined by the intensity of vortex in different direction.