Foxtail millet (Setaria italica (L.) Beauv.) may suffer from serious drought stress during their growth period, which affects their morphological characteristics and physiological metabolic activities. Previous studies identified that booting stage before heading is the most sensitive period to water shortage in foxtail millet development, but no detailed study on the response to drought stress was reported both with morphological and physiological traits. In this trial, morphological and physiological characteristics correlated with drought resistance index (DRI ) were monitored under both normal and drought stress conditions during booting stage using 20 foxtail millet cultivars. The results showed that relative panicle weight, grain weight per panicle, plant height, length of rachis and thousand-grain-weight (TGW) were significantly or very significantly correlated with DRI under drought conditions, which could be used as the morphological index to test drought resistance abilities. Relative chlorophyll, soluble protein, malondialdehyde（MDA）, and superoxide dismutase（SOD ）were significantly or very significantly correlated with DRI under drought condition, which could be used as the physiological index to identify drought resistance abilities in foxtail millet. Integrated drought resistance indexs including the relative TGW, panicle weight, chlorophyll, and superoxide dismutase （SOD ）content were selected by principal components analysis. The drought resistance performances of foxtail millet varieties in field conditions confirming its efficiency to predict the drought resistance during booting stage in foxtail millet using the integrated identification index and the recursive equation established in this study.