Abstract: The idea that the tending-to-one theorem on parameter sum of the difference equation for the controlled plant can be used as an auxiliary equation superposed weightily upon the difference equation itself, is proposed in order to allow all STR parameters to be estimated simulta-nuously. Thus, modified algorithms for STR and all-parameter adaptive controller are developed. Both algorithms possess the advantages of less computational effort, looser assumption on initial values for parameter estimation and quicker convergence rate.