<b>Anti Microbiological Assay Test or Antibiotic Assay Test of Pharmaceutical Preparation Containing Antibiotics using ‘Cylinder Plate Method’</b> In this paper, we are going to discuss the anti microbiological assay of the antibiotics. Aim of this paper is to predict the potency of the antibiotic preparation in reference with the working standard of the antibiotic and using the mathematical model in order to obtain the potency of the preparation in regards to its claim. Buffer solution, stock solution, standard solution, microbial culture selection, inoculum preparation, media preparation, mathematical model 2244-2247 Issue-5 Volume-3 Faiz Hashmi