Four novel amino thiadiazole containing rosin group were synthesized from the starting material of rosin or disproportionated rosin by purification, Diels-Alder addition reaction and cyclization reaction. Their structures were characterized by IR, 1HNMR, MS, and elemental analysis. Bactericidal activity of amino thiadiazole containing rosin group were evaluated by the minimum inhibition concentration. Preliminary results indicated that these compounds display extensive antibacterial activity. Especially compound 5-dehydroabietyl-2-amino-1,3,4-thiadiazole exhibit excellent antibacterial activity against Staphyloccocus aureu and Staphyloccocus epidermidis, their minimum inhibition concentration are 4μg/mL.