The objective of this work was to establish a scientific basis for the antibacterial action of chemical constituents isolated from Cordia myxa (Boraginaceae). The isolation and characterization of compounds were carried out respectively by using column chromatography, 1H NMR and 13C NMR, HSQC, HMBC, COSY, and by comparing with literature data. Compound 2 was tested on two gram (-) bacteria, E. coli and Salmonella typhi. in Mueller-Hinton agar and broth. Several classes of antibiotics were tested on the two strains; those with the best results were considered as references and methanol as the negative control. Two new terpenoids were isolated from the roots and branches of Cordia myxa. Compound 1, the 3β-urs-12, 20(30)-dien-28-oic-acid was isolated from the branches and compound 2, the Cordiridoid A which is a bisiridoid, was isolated from the roots. It is for the first time that, these compounds were described from the Cordia myxa and it is the first time that bisiridoids are reported from the Cordia genus. The results revealed the antibacterial activity on the bacterial strains at a dose-dependent. However, the larger dose of 40mg/ml had better antibacterial potential on both E. coli (diameter of inhibition zone, DIZ=19±0.1 mm; Minimum inhibition concentration, MIC=40mg/ml; MIC=0.5mg/ml) and Salmonella typhi (DIZ=22±0.1mm; 40mg/ml; MIC=0.28mg/ml) strains.