Milk samples were collected from 10 Surti buffaloes, maintained at Livestock Research Station, NAU, Navsari at 15th and 60th day postpartum to study relative gene expression of β-Casein milk protein and its transcription regulatory genes in primary bovine mammary epithelial cells (pBMEC). The total somatic cells were separated from milk samples through centrifugation. pBMEC were obtained from total somatic cells using antibody mediated magnetic separation method. Total RNA was extracted from pBMEC. Previously reported primers in cattle were used for amplification of β-casein milk protein and its transcription regulatory genes. The Somatic cell count and RNA yield from pBMEC were significantly higher at day 15 pp as compared to day 60 pp. The mean relative expression of CSN2, C/EBPβ, RUNX2, STAT5A and YY1 was found to be similar at both the stages of lactation.