Traditional method based on probabilistic transfer matrices (PTM) for estimate the effects of soft errors on gate level circuit reliability can only be used for combinational circuits.In this paper

a method for reliability estimation of sequential circuit based on PTM (S-PTM) is proposed.A sequential circuitis divided into an output logic module and a next state logic module

then the PTM of the sequential circuit is calculated by deduction employing the proposed PTM calculation model for sequential circuits in the paper.Considering probability distribution of the circuit inputs

the reliability of overall circuit is estimated.Experimental results on ISCAS 89 benchmark circuits show that our method is efficient.