Abstract: The purpose of the present investigation is to evaluate the effect of venturi throat velocity upon cavitation erosion of specimens for constant cavitation number, here based upon venturi discharge conditions. 1018 carbon steel and 1100-0 aluminum were tested in the Michigan (U-M) :high-speed cavitation tunnel with 27℃( 80F) tap water. Results of present tests are consistent with previous work done at U-M, showing that velocity-damage exponent varies over the range±to 5 for the velocity range of 10-49 m/s.