Weed can decrease the yield of plants 20% to 80% if they cannot be controlled, so weed control is absolutely necessary. Weed control by using a single herbicide continuously will cause weeds resistant, so it is necessary to mix herbicides. Combinations of herbicide with two or more types of active ingredient can be synergistic, additive, or antagonistic. The purpose of the study was to determine the characteristic of the herbicide mixture of Atrazine 500 g / l + Mesutrion 50 g / l for several types of weeds. The study was conducted in March -June 2017, at the Controlled Culture Laboratory, Padjadjaran University, Jatinangor. The treatment consisted of three types of herbicides with four levels of dosage, namely Atrazine herbicide (1080, 540, 270, 135, 0 g/ha), Mesutrion herbicide (196, 98, 49, 24.5, 0 g/ha) and herbicides mixtures Atrazine 500 g/L + Mesutrion 50 g/L (880,440, 220,110.0 g/ha) with four replications. Target weeds were Cyperus rotundus, Axonopus compressus, Digitaria sanguinalis, Ageratum conyzoides, Alternanthera piloxeroide, Cleome rutidosperma. Data were analyzed by linear regression analysis and MSM method to determine LD50 treatment and LD50 expectations. The results showed that Atrazine 500 g/L + Mesutrion 50 g/L Herbicides Mixed had a value of Hopeful LD50 of 0.097 g ai/ha and LD50 treatment value of 0.0283 g ai/ha with a co-toxicity of 3.416 (> 1) that indicating a synergistic mixture in the sixth weeds tested are A. conyzoides, A. piloxeroide, C. rutidosperma, C. rotundus, A. compressus, D. sanguinalis.