Based on 2003—2006 geomagnetic data of vertical component Z produced by Jiayuguan、Lanzhou and Tianshui observatory in Gansu province,we analyzed the characteristics of Sq variation,daily range and shape distortion.The result shows that in the different observatories,the daily shape is very similar.The lowest point displacement and flattening phenomenon,included in the shape distortion,usually occur in geomagnetic winter and show significant rules in Gansu province,which is closely related with daily range.