The asymptotical stability conditions for linear systems with interval time-varying delay are presented in terms of linear matrix inequalities. The conditions are less conservative than some existing ones and turn out to be greatly simplified version of the stability result previously reported by He etal. (2007). A distinct feature of the present criteria are that they are obtained by only using a simply integral inequality and are not involved any free-weighting matrices. This feature makes the computational burden of the criteria largely reduce. Numerical example is given to verify the effectiveness of the proposed criteria.