Based on the swelling-filling modification strategy, Nafion/silica composite membrane is facilely fabricated by non-destructively filling silica nano-particles into the Nafion framework. High temperature proton conductive performance of modified Nafion membrane is significantly enhanced due to the synergistic effect of maintaining the ordered nanophase-separated structure in Nafion and excellent water retention capacity of the silica fillers. Proton conductivity of the composite membrane is therefore raised to 33 mS/cm at 110 degrees C and 60% RH, which is enhanced by ca. 30% compared with the pristine Nafion. Taking account into the improved mechanical and oxidative stabilities attributed to the hydrogen bonding interaction between silica nano-particles and Nafion chains, high temperature fuel cell performance is measured and found to be remarkably improved by 37% at low humidity by considering the power density. (C) 2020 Elsevier Ltd. All rights reserved.