The present invention provides a method and apparatus for enrollment and evaluation of speaker authentication, a method for estimating discriminating ability of a speech, and a system for speaker authentication. A method for enrollment of speaker authentication, comprising: inputting a speech containing a password that is spoken by a speaker; obtaining a phoneme sequence from said inputted speech; estimating discriminating ability of the phoneme sequence based on a discriminating ability table that includes a discriminating ability for each phoneme; setting a discriminating threshold for said speech; and generating a speech template for said speech.