From 2006 to 2010, the herbicide produced by Syngenta Ltd. Company with trade name "Gramoxone 20SL" - one non-selective contact herbicide, had been evaluated in controling weeds in upland of Phu Tho and Yen Bai provinces. Gramoxone herbicide provides fast burndown control of most weeds without adverse effect on growth of maize, tea crop. The use of this herbicide has decreased erosion, soil runoff efficiently by leaving the soil a mulch and had a part in increasing crop yields, labor savings and raising production efficiency. Use of herbicide Gramoxone 20SL has also improved well microflora and microfauna, physical and chemical properties of cultivated soil due to a mulch leaved in the soil.