Abstract: For the purpose of investigating drought resistance of Agropyron cristatum,the seedlings were sampled in Osmotic stress conditions for examining the physiological indicators of praline acid, peroxidase （POD）,catalase （CAT）,malondialdehyde （MDA） and soluble sugar content, and Real-time qPCR analysis of PLD gene expression differences. The results showed that, under Osmotic stress,the changes of proline, POD and soluble sugar content correlated with PLD gene expression significantly on Agropyron cristatum. The research provided physiological understanding for drought resistance and a guide for germplasm screening of A gropyron cristatum.