In Taiwan, report of sysematic survey and study abDut the frnt diarrheas con - ixacel by swiling piglet axe still lacking. Therefore the occurrence of diarrheas among 3,639hcads of sw±lingpiglets from38l litters in the42 farms of the Northern, (Den - ta], Southern and Eastern districts of the whole wovince was dely survey and stutheri. The isolation and identification of the microorganisms of Escherichia cdi were carrier! out, the result was that in Taiwan, until the time weanlin& it was considered that the morbidity of diarrhea caused by Fscherichia coli arnouned to 76.1%, Mortality being 28.2%, and although the ratio was high, cornpased with the report of England or Den - mark it was nearly ewral. But the rate of occurrence for neonatal colilaificcis within a week after birth was 36.2%, Mortality 24.7%, comparel with other report, esjtially the report of Japan, the renrd was high.