The aim of the present work is to develop a self-diagnosis material with excellent sensing abilities via measurement of change in electrical resistance. A new self-diagnosis material, in which conductive RuO2 particles are dispersed in a glass matrix, was successfully fabricated by sintering at 850°C. The sensing properties of this self-diagnosis material were investigated in real time during tensile tests by measuring the electrical resistance change. The electrical resistance increased remarkably with increasing applied tensile load and materials showed excellent sensing performance at low strains <0.4% strain. The high sensitivity of the electrical resistance change is due to partial separation of the percolated structure between RuO2 particles, when microcracks form in the glass matrix. Sample were found to exhibit a residual electrical resistance after unloading during cyclic loading tests and the resistance value increased with increasing number of cycles.