Abstract: Changes of diastase activity, diastase isoenzmpe, soluble carbohydrate content,respiratory intensity of germinating Puccinellia tenuiflora seeds under sodium carbon ate stress were studied. The results are as follows:Diastas activity, soluble carbohy drate content, respiration intensity had a positive correlation with germinating process in salt free condition, but decreased compared with the control under sodium Carbonate stress and had a significant negative correlatinn with sodium carbonate concentration.The results indicates that the decrease of hydrolytic enzyme activity and the inhibition of the using of storing material and the inhibition of respiration is one of the reasons the Puccinellia tenuiflora seeds can't germinate under sodium carbonate stress.

Key words: Puccinellia tenuifolra, germination, sodium carbonate, diastase, isoenzyme, soluble carbohydrate, respiration