Ambrosia artemisiifolia is an annual herbaceous weed within the Asteraceae family, native to North America. In recent years, this species is increasingly present in Romanian crops (corn, sunflower, soybean, sugar beet), causing significant damage by decreasing the quantity and quality of production as well as by decreasing harvesting efficiency. A study by Coble et al. (1981) revealed that Ambrosia artemisiifolia, at a density of 4 plants per 10 m, reduced production of Glycine up to 8%. Similarly, Shurtleff and Coble (1985) followed by Weaver (2001) reported that at a density of 1.6 plants / m2, Ambrosia artemisiifolia caused a decrease in soybean production up to 12%. The damage caused by the common ragweed is numerous and continues to grow with along to its spreading into crops. Ambrosia artemisiifolia is a very competitive towards to soybean plants.  There are postermergent herbicides which control Ambrosia artemisiifolia in soybeans, but the weed's reaction can be altered if they are applied in mixture or with adjuvants that can influence the degree of control. This study aimed to assess the efficacy of herbicides in the population reduction of Ambrosia artemisiifolia from soybean culture.  The research was carried out in 2018, near Folea, Timis county. The experience included 9 variants / replicates. The substances used in the control of the species were:480 g/l bentazon + 22,4 g/l imazamox, 40 g/l imazamox, bentazon 480 g/l, wettol 100g/l, 50% tifensulfuron metal, applied in different doses. After application of herbicides, observations were made regarding their efficacy Ambrosia artemisiifolia population reduction, the appreciation was made after the EWRS scale, and at the end of the vegetation period the yield was determined. Applied herbicides had an efficacy in population reduction of Ambrosia artemisiifolia, ranging between 80-99%.The population of Ambrosia artemisiifolia was significantly reduced in the variants treated with 480 g / l bentazone + 22.4 g / l imazamox. The lowest control of this invasive species was achieved in the variant treated with 50% methyl thifensulfuron. Soybean yield correlated with the degree of control and had values ranging from 917.66 kg / ha to 3003.33 kg / ha.