Based on a dichotomy of knowledge content, this study examines how two types of external learning (i.e. technical and administrative learning) affect radical innovation, and assesses how such effects are conditional on two types of market dynamics (i.e. technological turbulence and competitive intensity). A survey of 183 high-tech firms in China shows that both technical and administrative learning facilitate development of radical innovation. Further, technological turbulence reduces the effect of technical learning but enhances the effect of administrative learning on radical innovation, whereas competitive intensity enhances the effect of technical learning but reduces the effect of administrative learning on radical innovation.