In this study, same biochemical characteristics, different antibiotics resistance states and R- factor transmissibility of 51 E. coli strain.s isolated from calves with diarrhea up to one week age were examined. Biochemical characteristics of the strains were found to be as follows: The rates for glucose, lactose, mannitol dulsitol, arabinose and adonitol fermentation tests were 100 %, 100%, 100 %, 54.9 %, 98.1 % and 21.6 % respectively and the rates for urease production, citrate utilization, tryp .. tophane deaminase, H2S, indol and .motility tests were 100 %, 0.0 %, 0.0 %, 0.0 %, 100%, 0.0 %, 96.1% and 80.4% resp€ctively. It was observed that only one of the whote strains ( 1.96 %) passessed a hemolytic activity. According to the results of disk diffusion method, antiıbiotic resistance rates of E. coli strains were determined as follows 70.5 % for tetracyline, 86.2 % for oxytetracyclin€ and neomisin, 98.1 % for erytromisin, 54.9% for ampisilin, 49.0 % for streptomisin, 23.4 % for chloramphenicole and 5.9% for nalidixic acide. Of the strains 94.1 per cent were resistant to more than 3 antibiotics. The rates of R-plasmid transmission of the strain were found to be 27.1 per cent.