Edwardsiella ictaluri is considered as one of the major pathogenic agents that causes disease in fish, necrotizes ogans such as liver, kidney spleen and brain of catfish, causing severe economic losses among fish farms in many countries. E. ictaluri - a Gram negative, short and rod shape bacterium (1 um in diameter and 2-3 um long), non-motile, non-spore formation, nagative for indole, H2S and urease production, positive for hemolysin, catalase and chondroitinase production. The comparison of 16S rDNA sequence showed that most bacteria strains isolated from Vietnam have high sequence similarity, and had over 99.6 percent 16S rDNA sequence similarity with the 16S rDNA sequence of Edwardsiella, indicating that they are all in the genus Edwardsiella. In addition with determination of eip18 specific gene of E. ictaluri, isolated bacterial strains from medical waste samples of Tra catfish from Vietnam were identified as the same species - E. ictaluri. So, it is indicated that E. ictaluri is one of the pathogenic bacteria that causes white lesion in liver, kidney and spleen in Tra catfish in Vietnam.