<p style='text-indent:20px;'>In this paper, we investigate a source identification problem for a class of abstract nonlocal differential equations in separable Hilbert spaces. The existence of mild solutions and strong solutions for the problem of identifying parameter are obtained. Furthermore, we study the continuous dependence on the data and the regularity of the mild solutions and strong solutions of nonlocal differential equations. Examples given in anomalous diffusion equations illustrate the existence and regularity results.</p>