Abstract: Based on the frequency-domain techniques to analyze the stability of a system‚this paper deals with the sufficient conditions of the asymptotic stability of linear neutral delay systems．According to the characteristic equation of the system‚a new sufficient criterion expressed in terms of the modulus matrix and the spectral radius was then ob-tained by using the theory of matrix analysis．This criterions is more conservative than those expressed by the matrix measure and matrix norm．The corresponding numerical examples show that the obtained results are effective and more conservative than those in the literatures．

Key words: frequency domain, neutral delay system, stability, spectral radius, conservativeness