Cirsium arvense Canada Thistle A perennial herb of the Compositeae family with deep roots and a final height of 120 cm. This plant is a weed of wheat, barley, tobacco, pastures, margins of roads and land, and can be restored after the drying of the air organs through its deep and creeping root system. Make In order to control the biological activity of this plant, Puccinia punctiformis was used as a biological herbaceous agent and sporulated on Canada thistle in the Neyshabour Agricultural College. Spring sporulation was performed once a year in spring of 1392-1394 on rainy days at a concentration of 2 *106 uredospore per ml on leaves. To provide optimal moisture, water was flushed over a weekly three times a day. For the preparation of urediospores wildlife plants that were naturally contaminated with fungi in the region, they were used. In addition to leaf inoculation, the crawling roots of the Canada Thistle were also inoculated by contaminated toothpaste.The result showed that the fungus developed three to five days after inoculation of pale spots on the leaf. Subsequently, Uredium sorus followed by telium sorus. In inoculated plants, in comparison with the control, severe weakness and general deterioration were observed, including small leaves and reduced growth. Flower production in treated plant or non-formed was either significantly reduced and the flowers formed were small and poor and the number of seeds in them was less than that of the control. In the third year, the number of Canada thistle decreased less than the first year, so its dominance disappeared.