This study assessed the rumen bypass potential of various protein sources at 24, 48 and 72 hr of incubation in rumen-cannulated cattle. The animal was fed with Napier and legume supplement following a ratio of 80:20. The incubation process followed the sequential addition method and digested samples were analyzed for percent dry matter and percent crude protein. Significantly lower dry matter digestibility and dry matter disappearance rate were noted using Flemingia (Flemingia macrophylla) leaf meal than in Calopo (Calopogonium muconoides), Kakawate (Gliricidia sepium), Pinto peanut (Arachis pintoi) and Soybean meal (SBM) in all rumen exposure times. Crude protein digestibility (CPD) and crude protein disappearance rate (CPDR) of Flemingia were significantly lower than Calopo, Kakawate, Pinto peanut and SBM at all periods which could be due to its high tannin content. Calopo had significant reduction in CPD and CPDR than Pinto peanut and SBM at 24 hr, SBM at 48 hr, and Kakawate and Pinto peanut at 72 hr and this could be due to its physical properties, maturity and source of leaves. The study suggests that Flemingia is a good source of bypass protein for ruminants.