The observation data by water tube tiltmeter,quartz horizontal extensometer and quartz pendulum tiltmeter at Lanzhou deformation station during 1994-1996 are analysed.The results show that anomaly of the tidal factors of M₂ wave appeared before the Yongdeng M_S5.8 earthquake on July 22,1995 and the Tianzhu M_S5.4 earthquake on June 1,1996.Accelerating anomalous change with rate greater after earthquake than before earthquake in tide daily average values are obvious before and after the two earthquakes.