In order to explore the drought characteristics and influencing factors in loess hilly region of Northern Shaanxi Province,three types of standardized precipitation evapotranspiration index(SPEI-HG,SPEI-TW,SPEI-PM)in different time scales(month,half year and year)were calculated using precipitation and three sets of potential evapotranspiration(ET)data based on daily climatic data collected from meteorological station of Suide in Shaanxi during 2000 to 2014.The ET was calculated by Hargreaves,Thornthwaite and Penman-Monteith formulae,respectively.Differences between the three types of SPEI were compared and an appropriate SPEI was selected.The drought characteristics were analyzed by the selected SPEI,and the sensitivity of meteorological factors to the selected SPEI was analyzed by path analysis.The results showed that 1)SPEI-PM could accurately describe drought events in loess hilly region of Northern Shaanxi Province.Compared with SPEI-PM,the SPEI-HG and SPEI-TW underestimate drought and the mean absolute errors were 0.26~0.38.2)Drought change showed a decreasing trend,SPEI-PM fluctuation was frequent in short time scale,and stable in long time scale.3)Meteorological factors that mainly affected SPEI-PM on the scale of monthly,half-year and year were the temperature,temperature and relative humidity,respectively.