... 0(8)First of all, we investigate an extention of the conditions for stable (see [12]) of solution of delaylinear diffirential equation under nonlinear perturbation. We recall that, the conditions ... (t))t≥0satisfies the hypothesis of theorem (2.3) then the solution of Eq.(12) in the case µ = 0 is asymptotic equivalence to the solution of Eq.(12) in the caseµ = 0.Ackowledgments. This paper is based on ... based on the talk given at the Conference on Mathematics, Mechanics,and Informatics, Hanoi, 7/10/2006, on the occasion of 50th Anniversary of Department of Mathematics,Mechanics and Informatics,...