In this study twelve samples of fermented milk product 6 Zabadi (three from farmhouse and three manufactured at industrial level Juhayna, Danone and Dina dairy companies). Also 6 Rayeb milk (three from farmhouse and the others from three above mentioned companies). The samples were obtained from local grocery shops in Sohag city. Chemical composition for all samples was determined. Also in vitro acid-buffering capacity (BC) was determined using a 10 % (dry matter) aqueous suspension titrated with 0.1N HCL until the pH reach 2 and then back titrated to pH 10 by addition 0.1N NaoH. The average resultant BC values were higher in farmhouse Rayeb milk 2.46 in comparison with 1.987 for Rayeb produced by industrial companies. Moreover the average Bc values for Zabadi produced by industrial companies was higher 1.992 than that obtained farmhouse house 1.693. The BC values for commercial antacids  Rrnnie and  Glycodal were 1.908 and 1.187 respectively.