A water quality measurement apparatus is provided. The apparatus comprises an electrochemical cell, a pH sensor, a temperature sensor, a control circuit, a power source, a database, and a warning device. The electrochemical cell comprises a working electrode, a reference electrode, and a counter electrode. The control circuit provides predetermined adjustable potentials between the reference electrode and the working electrode and measures electrochemical currents between the working electrode and the counter electrode, to form a current diagram based on the predetermined adjustable potentials and the electrochemical currents. The database stores predetermined reference diagrams based on various pH values and temperatures, and is in communication with the control circuit. The warning device is configured to output warnings, wherein the control circuit triggers the warning device in the condition that the current diagram exceeds the predetermined reference diagram based on the same range of the pH values and the temperatures.