Broiler were fed with 2%. 5% of native zeolite and 50 PPM aureonivcin.resspectiv ely. On 21 di. 31 th and 41 th days old, these chikens were experimentes infection with E. coli and Sal - pullonam by drinking water. The morbidity of chicken with zeolite or aureom - win was significantly lower than of contral chicken, the most eddective ration is chicken with ? o of zeolite, The result demonstrated that native zeotite could be considered as a feed supplement in replace of antibiotics for prophylasis of fowl bacterial diarrhea. The average hody weir.ht gain of late growing period (5 - 8th wkd old) of broiler with 2 o zeolite is better than that of broiler with 5%. it seems 2° zeolite is the more sui - table retion. In vitro. 9 ml of 5.6xl&”6 E. coli or Sal. pullorum mixed with 1 gm of na - tive zeolite, all bacteria were absorbed within 6 hrs. This result demonstrated that the na - tive zeolite has strong power on absorption of E. coli and Sal. pullorum.