The main portion of the paper is devoted for constructing approximated solutions of linear integral equations with multiple time lags (IEMTL) using two different types of basis functions B-spline functions and Orthogonal functions containing (Laguerre and Hermite) with the aid of expansion methods (collocation method, Partition method and Galerkin's method). Algorithms with the aid of Matlab language are derived for treating these equations using expansion methods. Comparison between the exact and approximated results of these methods with the aid of basis functions are given via two test examples and accurate results are achieved.