Protein base modification is a notable and potential method to alter the molecular structure, change the physicochemical and functional properties of the protein, thus affecting protein digestibility. This study is set out to investigate the protein digestibility of whey protein-lactose (WP-Lac) conjugates using an in-vitro infant digestion model. WP was conjugated using lactose by dry Maillard Reaction (MR) method under optimized conditions. WP-Lac heated at 40℃, water activity Aw=0.80 and incubation time from 0, 1, 3, 5, and 7 days were studied. To monitor the extent of conjugation, visible browning colour observation, ultraviolet-visible (UV-VIS) spectrophotometer, and L*a*b* analysis was performed using WP alone as a control in this study. Lactosylation will be then monitored with ortho-pthaldialdehyde (OPA) analysis to determine the primary amino groups present in both WP-Lac conjugates and WP alone (control). The covalent bond formation is observed between WP to lactose using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) technique. Under simulated gastric conditions at pH 3, 19uL of a 0.625 mg/mL pepsin is added to WP-Lac conjugates and WP alone (control), whereas in duodenal phase digestion, pH is set at 6.5 and 32uL of a 5.899mg/mL pancreatin is added to WP-Lac and WP (control). The digestion product affirms dry MR conjugation has the potential to improve WP digestibility. Herein, this study of WP-Lac conjugates will also explain its effect on WP digestibility, and it helps understand how WP-disaccharide glycate affects protein digestion during in-vitro infant digestion. Therefore, it could lead to the release of immunogenic protein by lactose and the development of hypoallergenic protein.