The objective of this research is to give an explanation why low-technology enterprises can catch up with high-technology ones even when they are unable to invest in R&D. The answer is the existence of technology diffusion, however, how does technology diffusion take place and can we quantify this process? To answer this question, we structure variables which represent the transmission channel of technology diffusion from high-technology enterprises to lowtechnology ones, then quantifying impacts of technology diffusion and applying this methodology into the analysis of impacts of technology diffusion on total factory productivity (TFP) convergence of Vietnamese enterprises. | How does technology diffusion increase speed of TFP convergence at firm level? Exploring the effects of high technology firms on linkages: Evidence from vietnam enterprises