In this paper, some strains of ETEC were first detected from the stools of the patients with cholerae-like diarrhea in China in 1974. With a detected rate 36.48% of ETEC Detected rates weve 20.18% from patients with acute diarrhea, 19.74% from environment and sea foods. ETEC produced most of LT toxin in culture medium when the they were incubated at 37-42 degrees C for 4 days. When Rabbit ileal loop test (RILT) was performed with the culture of ETEC or with germ-free culture supernatant, a large quantity of intestinal fluid in response to LT was accumulated at 24 hour and showed positive reaction at every test. Similar results were qained by using 5 cm or 10 cm ileal loop of RILT for LT detectoing. Better effects were noticed through injection of 1.0-3.0 ml culture of ETEC or germ-free enterotoxin in per 5 cm ileal loop. LT could be destroyed by heating at > 50 degrees C or pH < 4.0.