Based on the digital observation data of borehole volume strain at Liuhe seismic station near Nanjing city,Jiangsu province,from 2003 to 2008,the main disturbance factors as atmospheric pressure and rainfall are analyzed,and the short-imminent abnormality characteristics of the volume strain for 3 earthquakes in the range of predict efficiency are discussed.The results show that the atmospheric pressure in short period affect strongly to value of strain with synchronization on time,the positive correlation coefficient is 0.6～0.7.The effect of rainfall to the strain is complicate,depends on the process,duration time and volume of rain.Only rainfall accumulate to certain volume the solid tide can be distorted.But we still found some features between rainfall and volume strain.The volume strain at Liuhe station had significant short-imminent abnormalies in 1～2 months before regional moderate-strong earthquakes.