Proteins are an important nutrient for all animal species as they are a primary component of all body tissues as well as fluids and vital organs. In evaluating proteins present in halophytes as dietary nutrients, one should take several issues into consideration (ie. the high percentage of nonprotein nitrogen fraction, the large percent of solubility of halophytic proteins, the high degradability of soluble proteins in the rumen by the microorganisms, and the lack of readily available carbohydrates in halophytes that increases nitrogen waste). The protein contents of halophytes, amino acids in halophytes, effects of salinity on protein and amino acid contents of halophytes, effects of season on protein and amino acid contents of halophytes, animal utilization of halophytic proteins, and factors affecting microbial protein synthesis from halophytic sources are all covered in this chapter.