Abstract: The effect of holes on initial electrical resistivity and piezoresistive coefficients was investigated by taking constantan as an example. The relationship between average stresses and average electrical resistivity of an inhomogeneous composites with holes was replaced by that of a homogeneous material. The homogenization method was used to calculate initial electrical resistivity and piezoresistive coefficients of a square plate with holes. The conclusions can be summarized as follows. Initial electrical resistivity and piezoresistive coefficients π₁₁, π₂₂ of constantan material increase with the increase of volume fraction of holes, and piezoresistive coefficients π₁₂, π₂₁ decrease. Effect of triangle holes on initial electrical resistivity and piezoresistive coefficients of constantan material is the most obvious.