中文摘要：

根据角动量守恒原理，计算了地月系经潮汐演化到达平衡状态时的旋转周期和地月距离．并根据当前与平衡状态时地月系的总能量差，计算了到达平衡状态的时间．进而估计了地月距离变化和地球自转速率变化的长期趋势．

英文摘要：

The revolution period and the distance between the earth and the moon in the equilibrium state after tidal evolution of the earth-lunar system are calculated according to the principle of angular momentum conservation in this paper. The time for reaching to the equilibrium state is also computed on the basis of the difference between total energy of the earth-lunar system in present time and that in the equilibrium state. The long-period tendency of the variation of distance between the earth and the moon and that of the variation of the earth rotation rate are furthermore estimated.