For control process in the systems of differential equation with constant lag necessarycondition of optimality of singular control is found.
对带有常数滞后的微分方程系统的控制过程，我们给出了最优性的必要条件。
2
Two optimality functions for above optimal control models arc introduced, and the cquiva-lence between the optimality function and the one-order necessary optimality condition is concluded.