Abstract: A method for converter blow end-point control which comprises carrying out waste gas analyses on a continuous or intermittent basis in a final stage of the blow and, based on decarburization rate data (waste gas information) obtained from said waste gas analysis, determining the end-point of the blow where the carbon content of the bath equals a target carbon content. The method is characterized by the use of the decarburization rate equation: ##EQU1## which is a differential equation taking account of the delay time (.tau.) of said waste gas information which is a period of time from the time-point of occurrence of a decarburization reaction in the converter till the time when it is detected as said decarburization rate data, and an equation:b'=g(b)which is a functional equation for increasing the predictability of carbon content of the bath at the end-point of the blow.