Microbial transglutaminase (mTGase) crosslinking is a useful method for significantly improving the physical functionality of proteins. This study focused on the effect of mTGase modification on the functional properties of yak and cow caseins, including solubility, emulsifying property, water and oil absorption capacity, foaming property, and stability in the presence of Na⁺, Ca²⁺, and Mg²⁺. The results showed that the crosslinking degree of yak and cow caseins differed at the same mTGase concentration, but the change in functional properties of cow and yak caseins was similar. After mTGase crosslinking, the solubility of caseins decreased, while the emulsifying properties increased because of casein polymerization. MTGase crosslinking was very effective in improving water and oil absorption properties, stability in the presence of Na⁺, Ca²⁺, and Mg²⁺, and foaming activity, but did not affect the foam stability of cow acid caseins (caseins content of 94.22 %, w / w ) and yak acid caseins (caseins content of 94.28%, w / w ). The results could be used as a reference for selecting the proper modification method to improve the predetermined functional properties of caseins according to industrial processing requirements.