Model tests in a cavitation tunnel are necessary to predict cavitation erosion of ship propellers. Several erosion test methods have been developed such as paint test, aluminum erosion test etc. Paint test is usually used to predict the risk of erosion at many research institutes. In spite of its simplicity, the test results are affected much by slight change of testing procedures. This paper describes two new erosion test methods, which are aluminum plate erosion test and “Prescale” test. At the aluminum plate erosion test, a thin plate of pure aluminum is glued on a blade surface and its surface roughness increase is measured after erosion test at a cavitation tunnel. Impact pressure caused by cavity collapse can be measured using a pressure detecting film “Prescale” which was recently developed by a film company in Japan. Those two test methods were applied to five foil sections. From these experimental results, a close correlation between erosive intensity and fluctuation of cavity length was verified.