In this paper, we change the result as sum of principal minors and with the example we verify this method is more convenient in calculation and the result is more precise.
矩阵特征值的估计在理论和应用中都是非常重要的，传统的估计结果都是用矩阵的元素或范数来表示的，本文改为用主子式之和表示估计结果，并用实例验证了该方法计算较简便，结果更精确。
The stability of linear periodic coefficient systems are obtained by using the method of order principal minor determinant.
利用顺序主子式判别法得到线性周期系数系统的稳定性。
