Based on Hertz elastic contact theory, elastohydrodynamic lubrication theory, the equivalent radial stiffness model of roller raceway contact pair of logarithmic modified tapered roller bearing is derived under the consideration of oil film stiffness. The calculation results show that the equivalent radial contact stiffness increases with the increase of contact load, increases linearly with the increase of effective contact length of roller, and changes little with the increase of modification f1. When the radial load is small, the oil film has a great influence on the equivalent radial stiffness, which decreases gradually with the increase of the radial load.