An electronic trimeter for dead-srtop is here described.The circuit consists of a pentode D.C.amplifier and a cathode-ray tuning indicator.Adjustable porizing voltages(0.1-0.4V) for Pt electrodes are provided and the instrument has adjustable current sensitivity.It has been tested by the titration of Ⅰ₂ vs.S₂O₃⁼ and that of Cr₂O₇⁼ vs.Fe⁺⁺ in H₂S0₄ and in HCI.Results show that the end-point indication is sharp, sensitive and accurate.This titrimeter is expected to be applicable to most redox utrations.