The invention provides a nucleic acid construct for expressing an oxidative stress indicator, comprising a nucleic acid sequence encoding a partial protein, which contains at least the Neh2 domain sequence and is obtained by substantially deleting or functionally deleting the Neh1 domain sequence or the Neh1-Neh3 domain sequence in Nrf2 protein, a stress-inducible promoter sequence, which is located upstream the nucleic acid sequence, and a nucleic acid sequence, which encodes a protein capable of emitting a detectable signal and is located downstream the nucleic acid sequence. The invention also provides a method for measuring oxidative stress and a method for screening an oxidative stress inhibitor, each using the nucleic acid construct.