This study was carried out for determination of the minimal inhibitory concentration of enrofloxacin and flumequine giving inhibition zone by using microbiological assay technique and determination of the withdrawal time of enrofloxacin and flumequine after oral application as well as the incidence of inhibitory substance in table eggs marketed in Alexandria, Behera and Kafr El-Aheikh governorates. The MICS of enrofloxacin using E. Coli, P.fluorecens ,K pneumoniae and B. subtilus as test organisms were 0.022, 0.12, 0.054 and 0.096 ug/ml while MICS OF flumequine using the same test organismes were 0.04, 0.17, 0.096 and. 022ug/ml respectively. Enrofloxacin residues could be detected at the 2nd day of oral adminstration and last for 2 days in albumen, and 4 days after last dose of application, while flumequine last for 3 days in albumen and 2 days in yolk after the last dose of application. The inhibitory substances in the examined egg samples perchased from Alexandria, Behera and Kafr El-Sheikh governorates were, 70, 62 and 24%,78,82 and 16% and 84,64 and 48% of brown, white and Balady table eggs respectively.