In this paper, the activity of POD, content of MDA and plant polyphenols in Tamarix rasosissima were measured by spectrophotometry on the basis of field investigation and sampling. The reflections of POD and MDA, under different soil water, were analyzed. Emphasis was placed on the content polyphenols in different tissues, sites, seasons, plant ages and soil water content. The following results were concluded: As a decreasing of soil water content, the activities of POD increased at first, but declined in a...