Wild taro, a natural type of taro that thrives in many countries, has been used as food for humans and animals, and in traditional medicine since ancient times, but with little research. The aims of the study were to investigate of morphological and anatomical vegetative characteristics, determinate chromosome number, preliminary determinate chemical composition, and assess antibacteria activity against E. coli and B. subtilis of “green” morphotype wild taro (Colocasia esculenta (L.) Schott.) at CanTho city, Viet Nam. The transverse sections of leaf and tuber were double-stained with carmine alum laque–iodin green dye to investigate anatomical properties. The root tips were pretreated by hypo-osmotic shock and double-dyed with aceto-carmine to estimate chromosome number. Phytochemical compositions and antibacterial activity against Escherichia coli and Bacillus subtilis were detected on leaf and tuber extraction by reagents and well difusion method. The results showed morphological and anatomical characters of fresh leaf blade, petiole, root, and corm of “green” wild taro. The chromosome number at root tip was 2n = 28. “Green” wild taro C. esculenta contained organic compounds such as steroids, flavonoids, alkaloids, saponins, tannins, coumarines, and glycosides. Both leaf and tuber extracts showed antibacterial activity against the tested bacteria. This wild taro was indicated to be more effective against gram-negative bacteria than gram-positive bacteria.