This research was conducted in order to investigate rumen degradability of some factors includes; Dray Matter (DM), Organic Matter (OM), Crude Protein (CP), Acid Detergent Fiber (ADF) in three different plant protein supplements includes; soybean, canola and cottonseed meal. The experiment was carried out using in three castrated and fistulated male Zel sheep. Each feedstuff was weighed into duplicate nylon bags and incubated in each of the three rumen fistulated sheep for 0, 2, 4, 8, 16, 24 and 48 h. Results revealed that effective degradability of DM of soybean, canola and cottonseed meal were 55.8, 73.8 and 48.5%, respectively. Effective degradabilities of the CP in feedstuffs were 55.8, 62 and 48.3% for the respective feedstuffs. Effective degradabilities of the OM were 55.7, 56.4 and 47.4%, respectively. Results also showed that effective degradabilities of the ADF were 55, 56.4 and 37.6, respectively. According to the results the researchers concluded that canola and soybean were more degradable in the rumen of the sheep while cottonseed meal were less degradable and, hence resulted in higher rumen undegradable protein.