In this paper, we consider an inverse problem with a time-dependentcoefficient. This problem is ill-posed. To regularize this problem, we use theintegral truncation method combined with the quasi-boundary value method. Weconstruct approximate solutions and consider the stability of such a solution. Moreover, we evaluate the errors between regularized solutions and exact solutions.A numerical method is given to illustrate the theoretically obtained results.In this paper, we consider an inverse problem with a time-dependentcoefficient. This problem is ill-posed. To regularize this problem, we use theintegral truncation method combined with the quasi-boundary value method. Weconstruct approximate solutions and consider the stability of such a solution. Moreover, we evaluate the errors between regularized solutions and exact solutions.A numerical method is given to illustrate the theoretically obtained results.