Since 1983 it has been reported many times that the tensile strength of a liquid has a noticeable influence onincipient cavitation test[1,2,3].In this paper some results indicate the characters of tensile strength of test wa-ter in different cavitation test facilities for example;characters in normal cavitation tunnel without free surfaceand in depression tank with free surface respectively.For getting a comparable and stable test result of cavitationinception it is important to know the tensile strength of test water and to keep it stable. Since 1983 it has been reported many times that the tensile strength of a liquid has a noticeable influence onincipient cavitation test [1,2,3]. In this paper some results indicating the characters of tensile strength of test wa-ter in different cavitation test facilities for example; characters in normal cavitation tunnel without free surfaceand in depression tank with free surface respectively. For getting a comparable and stable test result of cavitationinception it is important to know the tensile strength of test water and to keep it stable.