Abstract: Laboratory tests are conducted to investigate the influence of ferrum and cuprum electrodes on electroosmotic effects, and they are analyzed and compared through drainage, voltage loss at the electrodes and water content monitoring. The results demonstrate a better performance of ferrum electrode than that of cuprum electrode. In the case of cuprum anode, a rapid decrease in current is observed for 4~6 hours after the test commences, together with a big voltage loss at the anode. Furthermore, the influence of different combinations of cathode and anode materials on electroosmosis is also explored. It is revealed that the anode materials occupy a leading role in electroosmosis while the cathode materials display little effect. A reasonable explanation to the laboratory findings in terms of electrochemistry is also given. The phenomenon of electrochemical passivation is first discovered in elecroosmosis. The electrochemical passivation will reduce the efficiency of elecroosmosis substantially and should be avoided in practical engineering.