Strain gauge is a very important unit in material tensile test. In terms of measure principle,strain gauge is one of the best high-precision measure units,but the actual measure results always fail to give the correct values in some unknown reason.Obviously,this will cause the error of other values such as Young's modulus. In order to use strain gauge in effective way,series of tensile tests have been done in this paper to give a quantitative analysis to explore main factors that cause the low precision of ...